Operating circuit in magnetic resonance system

Abstract

In a general aspect, a magnetic resonance system is operated. In some embodiments, an amplifier circuit for the magnetic resonance system includes first and second switch devices, a high-power amplifier (HPA) device, and a power combiner device. The first switch device includes an input port and two output ports. The HPA device includes an HPA input port and an HPA output port. The HPA input port is coupled to the first output port of the first switch device. The second switch device includes an input port and an output port. The power combiner device includes two input ports and an output port. The first input port of the power combiner device is coupled to the output port of the second switch device. The second input port of the power combiner device is coupled to the second output port of the first switch device along a path that bypasses the HPA device.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 438,407, entitled "Operating Circuitry in a Magnetic Resonance System," filed February 6, 2023. The above-referenced priority document is incorporated herein by reference in its entirety.

[0002] The following description relates to operating circuits in a magnetic resonance system. [Background technology]

[0003] Magnetic resonance systems are used to study a wide variety of samples and phenomena. In some magnetic resonance applications, spins in a sample are polarized by an external static magnetic field, and a resonator manipulates the spins by generating a magnetic field at a frequency near the resonant frequency of the spins. Magnetic resonance applications include, for example, electron paramagnetic resonance (EPR), nuclear magnetic resonance (NMR), and magnetic resonance imaging (MRI). [Brief explanation of the drawings]

[0004] [Figure 1] 1 is a schematic diagram illustrating aspects of an exemplary magnetic resonance system. [Figure 2] FIG. 1 is a schematic diagram illustrating aspects of an example amplifier circuit. [Figure 3] 3 is a flow chart illustrating aspects of an example process for operating the example amplifier circuit shown in FIG. 2. [Figure 4A] 1A and 1B are schematic diagrams illustrating aspects of exemplary resonator circuits. [Figure 4B] 1A and 1B are schematic diagrams illustrating aspects of exemplary resonator circuits. [Figure 5]4A-4B are flow diagrams illustrating aspects of an example process for operating the example resonator circuit shown in FIGS. 4A-4B. [Figure 6A] 1A and 1B are schematic diagrams illustrating aspects of exemplary resonator circuits. [Figure 6B] 1A and 1B are schematic diagrams illustrating aspects of exemplary resonator circuits. [Figure 7] 6A-6B are flow diagrams illustrating aspects of an example process for operating the example resonator circuit shown in FIGS. 6A-6B. [Figure 8A] FIG. 10 is a timing diagram illustrating aspects of an example control sequence. [Figure 8B] FIG. 10 is a timing diagram illustrating aspects of an example control sequence. DETAILED DESCRIPTION OF THE INVENTION

[0005] In some aspects of what is described herein, a magnetic resonance system includes electromagnetic circuitry that provides new or improved operational capabilities, which may include, for example, the ability to switch between various operational modes. In some examples, the magnetic resonance system includes hardware components and control logic that enable the magnetic resonance system to switch between a continuous-wave (CW) mode of operation and a pulsed mode of operation. In some examples, the magnetic resonance system includes hardware components and control logic that enable the magnetic resonance system to switch between a mode in which a sample is measured (e.g., using continuous-wave spectroscopy or pulsed spectroscopy) and a mode in which a pulse is monitored (e.g., for transient digitization / correction, etc.). Other operational modes are also possible.

[0006] In some implementations, the electromagnetic circuit includes a switch device that enables the electronic circuit to switch between different states representing different operating modes of the magnetic resonance system. In some cases, the switch device has a fast switching time and can be controlled by a digital control signal, thereby reducing dead time and providing digitally controlled mode selection. In some cases, the electromagnetic circuit can operate at cryogenic temperatures, which can reduce the effects of room temperature noise and improve output efficiency. For example, in some embodiments, the switch device can be used in a cryogenic environment to prevent room temperature noise from reaching a cryogenic low-noise amplifier (LNA) device, maximize power handling, or provide a combination of these and possibly other benefits. In some embodiments, the cryogenic LNA device is phase and amplitude stable.

[0007] In some implementations, the systems and techniques described herein offer technical advantages over existing technology. For example, the size and complexity of electronic circuit components (e.g., of high-power amplifier devices) can be reduced because voltage is more efficiently converted into a control field. In some implementations, the electromagnetic circuits described herein can enable real-time monitoring of pulse transient behavior and transient impulse control, which can be used to improve the accuracy and precision of magnetic resonance control signals. In some implementations, the electromagnetic circuits described herein can enable arbitrary nanosecond timescale switching between pulsed and CW modes of operation, for example, even within the same magnetic resonance experiment. In some cases, the systems and techniques described herein can provide shared hardware resources for magnetic resonance measurements in different modes, enabling the ability to switch between pulsed and CW modes of operation without hardware modifications to the magnetic resonance system.

[0008] In some implementations, the systems and techniques described herein can enable automated operation of the magnetic resonance system, which may include automatic (e.g., programmed) switching between different operating modes. Such automation can improve sample throughput, for example, by enabling system control with minimal or no human intervention or modification. In some implementations, the systems and techniques described herein can enable closed-loop adaptive experimental design, for example, by incorporating software and system control interfaces designed for ease of automation.

[0009] Aspects of the systems and techniques described herein can be adapted for various types of magnetic resonance systems. For example, electromagnetic circuits or circuit elements can be adapted for nuclear magnetic resonance ("NMR") systems, electron paramagnetic resonance ("EPR") systems, or other types of magnetic resonance systems. As another example, all or a portion of the electromagnetic circuit can be deployed on a probe of a magnetic resonance system, or the electromagnetic circuit can be deployed in a probeless magnetic resonance system. In some cases, the electromagnetic circuit (e.g., a resonator or other components) can be adapted to operate with liquid samples, solid samples, liquid crystal samples, biological samples (e.g., blood samples), or other types of samples measured or otherwise analyzed by a magnetic resonance system. As another example, certain electromagnetic circuits can operate in cryogenic environments (e.g., 77 K, 4 K, or other cryogenic temperatures below 273 K), or the electromagnetic circuit can operate at non-cryogenic temperatures, including room temperature.

[0010] In some cases, the systems and techniques described herein may be compatible with multiple different types of resonators, cryogenic systems, probe configurations, and other components in various magnetic resonance systems. For example, the electronic circuitry may be designed to be compatible with non-superconducting and superconducting resonators (which may include superconducting resonators fabricated with various superconducting materials). The resonators may be, for example, microstrip, cavity, coil, coplanar waveguide, or other types of resonators for magnetic resonance systems. Furthermore, the resonators may be, for example, rectangular cavity resonators, cylindrical cavity resonators, dielectric resonators, loop gap resonators, or any lumped element resonator. In some cases, the electronic circuitry described herein may be deployed in various cryogenic systems, including, for example, compact closed-cycle systems, open-cycle systems, and liquid cryogenic systems. In some cases, the electronic circuitry described herein may be deployable in various compact probe designs, thereby enabling the use of low-noise cryogenic receiver amplifiers in various configurations without interfering with sample exchange methods. In some cases, a combination of these advantages and potentially other advantages and improvements may be achieved.

[0011] Aspects of the systems and techniques described herein can be adapted for various types of applications. For example, the systems and techniques described herein can be used for structural biometrics, e.g., measuring structural properties of proteins or protein complexes in a biological sample (e.g., a blood sample, a urine sample, or other type of biological sample). Such measurements can be useful in clinical applications, e.g., diagnostics, therapeutics, pharmaceutical drug discovery / development, and understanding membrane protein structure and function, among other applications.

[0012] FIG. 1 is a schematic diagram illustrating an embodiment of an example magnetic resonance system 100. In general, the magnetic resonance system 100 can be an EPR system, an NMR system, or other types of magnetic resonance systems. The example magnetic resonance system 100 includes a signal processing unit 102, a spectrometer unit 104, an amplifier unit 106, a resonator unit 108, a receiver unit 110, a temperature control unit (TCU) 112, and a field control unit (FCU) 114. In some embodiments, each of these units of the magnetic resonance system 100 can include associated electronic circuitry and other components, including housings, ports, etc. In some embodiments, the example magnetic resonance system 100 can include additional or different components, and the components can be arranged as shown or in another manner.

[0013] As shown in FIG. 1 , the signal processing unit 102 includes a controller unit 122, a digital-to-analog converter (DAC) device 124, an analog-to-digital converter (ADC) device 128, and a digital input / output (DIO) unit 130. In some embodiments, the signal processing unit 102 may include additional or different components, and the components may be arranged as shown or in another manner. For example, while FIG. 1 shows two DAC devices (124A, 124B) and two ADC devices (128A, 128B), the signal processing unit 102 may include additional DAC and ADC devices, additional DIO units, etc. In some cases, the ADC device 128B may be an auxiliary device and may be configured to receive and process signals from units within the magnetic resonance system 100 of FIG. 1 or a different system. As another example, the signal processing unit 102 may include one or more central processing units (CPUs), memory units, and computer elements. The one or more CPUs may interface with the controller unit 122 for sending control signals and receiving data, and may interface with the TCU 112 and the FCU 114. The CPUs may be controlled by software and may execute pre-configured programs stored in the memory units to perform magnetic resonance experiments.

[0014] In some implementations, the controller unit 122 controls the output of the DAC device 124 and the input of the ADC device 128 to generate digital control signals and synchronize the phase and timing between several components in the magnetic resonance system 100. In the illustrated example, the signal processing unit 102 delivers analog control signals to the spectrometer unit 104. The analog control signals generated by the signal processing unit 102 can be implemented as amplitude, phase, and frequency modulation of an intermediate frequency (IF) carrier signal. In the illustrated example, the signal processing unit 102 also delivers digital control signals to other components in the magnetic resonance system 100 (e.g., the spectrometer unit 104, the amplifier unit 106, the resonator unit 108, the receiver unit 110, etc.). For example, the digital control signals can be delivered to switch devices (e.g., switch devices 202, 206, 402, 406, 602, 606 in FIGS. 2, 4A-4B, and 6A-6B) or other types of electronic components. The signal processing unit 102 can receive magnetic resonance detection signals and / or sensor output signals from devices within the resonator unit 108. These signals may be received as amplitude, phase, and frequency modulation of an IF carrier wave and can be digitized for further processing (e.g., for measurement, pulse transient control and correction, etc.). In some cases, the controller unit 122 may include a field programmable gate array (FPGA) device, a digital signal processing (DSP) unit, or other type of data processing device.

[0015] In some implementations, the controller unit 122 is configured to send digital signals to the DAC devices 124A, 124B, receive digital signals from the ADC devices 128A, 128B, and send digital control signals to the DIO unit 130. The signal processing unit 102 may be configured to perform signal averaging and digital signal processing. Specifically, the controller unit 122 can be configured to generate amplitude-, phase-, and frequency-modulated AWG pulses at a digital intermediate frequency (IF). The output signals from the DAC devices 124A, 124B, the ADC devices 128A, 128B, and the DIO unit 130 can be time-synchronized (e.g., phase-coherent) and controlled by the control unit 122 according to a pulse program. In some implementations, signal acquisition from the resonator devices in the resonator unit 108 can be digitized in a phase-coherent manner at the IF and digitally demodulated for phase-sensitive detection, which can also be controlled by the control unit 122. In some implementations, the signal processing unit 102 enables digital pulse generation and detection with time-synchronized, phase-coherent DAC, ADC, and DIO operations.

[0016] In the illustrated embodiment, DAC devices 124A, 124B are configured to generate analog IF I and Q quadrature control signals from the digital IF signals, and ADC devices 128A, 128B are configured to digitize the magnetic resonance detection signals (e.g., spin signals) or sensor output signals and transmit the digitized signals to controller unit 122 for processing. The example DIO unit 130 converts digital control toggle signals from controller unit 122 into digital control signals. The digital control signals can be time-locked to the analog IF control signals generated by DAC devices 124A, 124B and the magnetic resonance detection signals or sensor output signals received by ADC device 128.

[0017] The spectrometer unit 104 may include microwave or radio frequency hardware components (e.g., switches, mixers, amplifiers, attenuators, etc.) that generate and receive microwave or radio frequency signals. For example, the spectrometer unit 104 may be configured to process single-sideband X-band (8-12 GHz) signals. In some implementations, the spectrometer unit 104 may include a low-phase-noise microwave synthesizer for generating a system master oscillator signal and an analog spectrometer local oscillator signal, and a local oscillator suppression and image suppression (LOS) synthesizer for converting microwave control pulses to single-sideband signals that can be applied to the resonator unit 108.

[0018]

number

number

[0019] In some implementations, the amplifier unit 106 is digitally controllable to rapidly switch between pulsed and continuous wave modes of operation. For example, the amplifier unit 106 is digitally controllable by a digital control signal from the signal processing unit 102. In some cases, the amplifier unit 106 may include one or more switch devices and an HPA device. The example amplifier unit 106 includes an amplifier circuit that can be implemented as the example amplifier circuit 200 of FIG. 2 or in other manners. In some implementations, the amplifier unit 106 operates at an elevated temperature, e.g., room temperature, outside of the cryogenic environment.

[0020] In some implementations, the resonator unit 108 operates in one or more cryogenic cryogenic environments, for example, in a cryostat. In some implementations, the resonator unit 108 operates at an elevated temperature, for example, room temperature, outside of the cryogenic environment. An example resonator unit 108 may include an amplifier device (e.g., a cryogenic LNA device) integrated into or otherwise connectable to the resonator device. The resonator unit 108 is controllable to switch between operating modes, for example, a magnetic resonance measurement mode and a pulse transient digitization / correction mode. An example resonator unit 108 may include, for example, a resonator device for generating an electromagnetic field in a sample volume of a magnetic resonance system, signal wiring for transmitting microwave signals and digital control signals, cryogenic receiver components, and built-in hardware for temperature setting and stabilization. The resonator unit 108 includes a resonator circuit that may be implemented as any of the example resonator circuits 400, 430, 600, and 630 of FIGS. 4A-4B and 6A-6B, or in other manners.

[0021] In some implementations, the receiver unit 110 may receive signals from the resonator unit 108 (e.g., magnetic resonance detection signals from the resonator, sensor signals from the sensor device) and synchronize the received signals with a local oscillator frequency (f LO ) by mixing with the intermediate frequency (f IF) from the mixer device. The receiver unit 110 includes a filter device to remove undesired frequency components, e.g., f LO -f IF The receiver bandwidth (±f IF ) to suppress noise external to the receiver unit 110. The receiver unit 110 may also include other components, such as an IF amplifier device, a low-pass filter device, and other circuit components. In some implementations, the receiver unit 110 is configured to downconvert the magnetic resonance detection signal or sensor signal to an IF signal. In some cases, the receiver unit 110 includes various stages of filtering and amplification to reduce noise bandwidth. The example receiver unit 110 shown in FIG. 1 can receive both a low-level spin signal input and a high-level pulse transient digitized input.

[0022] In some implementations, the TCU 112 may be configured and operated to monitor and stabilize the temperature of the cryogenic environment in which the resonator unit 108 resides. For example, the TCU 112 may measure and stabilize the temperature of various components using closed-loop feedback control. In some cases, the FCU 114 may be configured and operated to monitor, stabilize, and vary a primary magnetic field within the magnetic resonance system. The primary magnetic field is an external B0 magnetic field (quantized magnetic field) applied to the sample volume and generated by a primary magnet system, which may be implemented as an electromagnet, permanent magnet, superconducting magnet, or other type of magnet system. For example, the FCU 114 may measure and stabilize the quantized magnetic field using closed-loop feedback control. The FCU 114 of the magnetic resonance system 100 may include a magnet configured to generate a magnetic field corresponding to X-band spin resonance (e.g., a magnetic field strength in the range of approximately 0 to 4000 G).

[0023] In some cases, the example magnetic resonance system 100 may include other components. For example, the magnetic resonance system 100 may include an electromagnet power supply and a Hall probe that interface with the FCU 114 to receive control signals from and apply appropriate currents to the primary magnet system. The example magnetic resonance system 100 may include a helium or nitrogen cooled cryostat that can be maintained at extremely low temperatures (e.g., below 1 K or other cryogenic temperatures). In some cases, the cryostat of the example magnetic resonance system 100 includes built-in control hardware for temperature setting and stabilization.

[0024] In some modes of operation, a primary magnet system generates a primary magnetic field within the controlled environment of a sample volume in the magnetic resonance system 100. The primary magnetic field is typically applied to a sample in the sample volume near a resonator in the resonator unit 108. In various implementations, the primary magnetic field can be homogenous throughout the volume of the sample volume. In some cases, a gradient system generates one or more magnetic gradient fields that vary spatially across the sample volume. Generally, the primary magnetic field generated by the primary magnet system quantizes the spin states and sets the Larmor frequency of the spin ensemble.

[0025] In some modes of operation, a spin ensemble in the sample interacts with a resonator device in the resonator unit 108. Control of the spins in the sample can be achieved, for example, by a radio frequency or microwave magnetic field generated by the resonator device. The drive frequency can be tuned to the resonant frequency of the spins, which is determined by the strength of the primary magnetic field and the gyromagnetic ratio of the spins. The spins can be a collection of particles with non-zero spin that magnetically interact with the applied magnetic field. For example, the spin ensemble can include nuclear spins, electron spins, or a combination of nuclear and electron spins. Examples of nuclear spins include hydrogen nuclei (H), carbon-13 nuclei (C), etc. In some implementations, the spin ensemble is a collection of identical spin-½ free electron spins associated with a collection of macromolecules.

[0026] 1 , the spectrometer unit 104 and the amplifier unit 106 are electromagnetically coupled to the resonator unit 108 (e.g., by coaxial cables, waveguides, etc.) and are adapted to communicate with the resonator unit 108. For example, the amplifier unit 106 may be adapted to provide a voltage signal or a current signal that drives a resonator in the resonator unit 108. In the example shown in FIG. 1 , the receiver unit 110 acquires magnetic resonance data based on a control signal delivered to the resonator unit 108. For example, the receiver unit 110 may receive a magnetic resonance detection signal generated by an interaction between the resonator and a sample contained in the resonator unit 108 based on a magnetic resonance control signal received at the resonator device.

[0027] In some cases, the signal processing unit 102 communicates with a computer system. The computer system may include one or more digital electronic controllers, microprocessors, or other types of data processing devices. The computer system may include memory, a processor, and may operate as a general-purpose computer, or the computer system may operate as an application-specific device. The computer system may be used to generate control sequences (e.g., pulse sequences), analyze or display data, program pulses, or obtain user input (e.g., via a user interface, through a communications port, or otherwise), or perform other types of operations.

[0028] In some aspects of operation, the exemplary magnetic resonance system 100 operates in a continuous wave (CW) mode of operation, e.g., using CW EPR or CW NMR spectroscopy. In a typical CW spectroscopy experiment, the resonator applies a low-power continuous excitation field (e.g., a radio frequency or microwave frequency Raman field) to the sample for a relatively long period (e.g., relative to the intrinsic relaxation time) to bring the spin ensemble to a steady state. The resonant frequency of the spins is swept over a range (by sweeping the main magnetic field) and the resulting response spectrum is measured.

[0029] In some aspects of operation, the exemplary magnetic resonance system 100 operates in a pulsed mode of operation, for example, using pulsed EPR or pulsed NMR spectroscopy. In a typical pulsed spectroscopy experiment, the resonator applies a sequence of intense, high-power pulses (e.g., radio frequency or microwave pulses) to the sample while the main magnetic field is held constant. The resulting spin states can then be observed, for example, by acquiring free induction decay (FID), which can then be Fourier transformed to obtain a spectrum.

[0030] The exemplary magnetic resonance system 100 includes electronic components for both CW and pulsed modes of operation, allowing the system 100 to switch between these modes of operation without hardware modifications or other intervention. For example, the controller unit 122 can cause the amplifier unit 106 and the resonator unit 108 to switch from a CW mode of operation to a pulsed mode of operation or from a pulsed mode of operation to a CW mode of operation, the mode of operation being selectable by controlling one or more of the digital control signals generated, for example, by the DIO unit 130.

[0031] In some modes of operation, the exemplary magnetic resonance system 100 operates in a normal mode of magnetic resonance measurement. For example, the magnetic resonance system 100 can perform CW EPR or CW NMR spectroscopy, pulsed ESR or pulsed NMR spectroscopy, or other types of magnetic resonance experiments. In these modes of operation, a magnetic resonance control signal is delivered to a resonator (within the resonator unit 108), which causes the resonator to generate a magnetic resonance control field (pulsed or CW) that is applied to spins in a sample. A magnetic resonance detection signal is acquired (e.g., due to the interaction of the spins with the resonator) and processed to measure the response of the spins to the control field.

[0032] In some aspects of operation, the exemplary magnetic resonance system 100 operates in a pulse-observation mode of operation (also referred to as a pulse-transient digitization / correction mode). In the pulse-observation mode, a magnetic resonance control signal is delivered to a resonator (within the resonator unit 108) to observe the magnetic resonance control signal delivered to the resonator and / or the magnetic resonance control field generated by the resonator. Observing the magnetic resonance control signal at the resonator and / or the magnetic resonance control field generated by the resonator allows for more accurate calibration of the control signal and correction of errors. In general, the magnetic resonance control signal as seen by the resonator in the resonator unit 108 is not identical to the magnetic resonance control signal as generated by the spectrometer unit 104. Similarly, the magnetic resonance control field as seen by the sample in the resonator unit 108 is not identical to the predicted control field. These types of discrepancies can be measured (e.g., by digitizing and analyzing the observed signal), and enhanced control techniques can be implemented to improve the precision and accuracy of the control achieved by the magnetic resonance control signal. For example, the control sequence can be calibrated to take into account pulse transients and other types of noise.

[0033] The illustrative magnetic resonance system 100 includes electronic components for both a normal mode and a pulsed observation mode of operation, allowing the system 100 to switch between modes of operation without hardware modifications or other intervention. For example, the controller unit 122 can cause the resonator unit 108 to switch from a pulsed observation mode of operation to a normal mode of operation, or from a normal mode of operation to a pulsed observation mode of operation, the mode of operation being selectable by controlling, for example, one or more of the digital control signals generated by the DIO unit 130. As an example, the magnetic resonance system 100 can operate in a pulsed observation mode to observe (and possibly take into account) pulsed transients or other types of phenomena, and then switch to a normal mode of magnetic resonance measurement to measure a sample.

[0034] FIG. 2 is a schematic diagram illustrating an embodiment of an example amplifier circuit 200. In some implementations, the example amplifier circuit 200 is deployed as part of a magnetic resonance system, for example, in the bypass unit 106 of the example magnetic resonance system 100 of FIG. 1 . The example amplifier circuit 200 can be used in magnetic resonance experiments and is configured to switch the magnetic resonance system between a continuous wave mode of operation and a pulsed mode of operation. As shown in FIG. 2 , the example amplifier circuit 200 includes various circuit components, including a first switch device 202, a high-power amplifier (HPA) device 204, a second switch device 206, a bandpass filter device 208, and a power combiner device 210, disposed between an input port 212A and an output port 212B of the amplifier circuit 200. In some implementations, the example amplifier circuit 200 includes an interface configured to connect the circuit components to each other, for example, via a waveguide, a coaxial cable, a metallic wiring or feed line, or other type of signal line.

[0035] In some cases, the example amplifier circuit 200 resides in an elevated temperature (e.g., room temperature) environment outside of the cryogenic environment in which the resonator device and, possibly, other components of the magnetic resonance system reside. In some implementations, the example amplifier circuit 200 receives a magnetic resonance control signal from a spectrometer circuit (e.g., in the spectrometer unit 104 of FIG. 1 ) at input port 212A and delivers an output signal to the resonator circuit (e.g., in the resonator unit 108 of FIG. 1 ) via output port 212B. The example amplifier circuit 200 may include additional or different components, and the components may be arranged as shown or in other manners. For example, bandpass filter devices and limiter devices may be configured in various locations within the amplifier circuit 200. In some cases, the example amplifier circuit 200 may be operated according to the operations in the example process 300 of FIG. 3 based on control sequences of the types shown in FIGS. 8A-8B or in other manners.

[0036] 2, first switch device 202 has an input port, a first output port, a second output port, and a control port, HPA device 204 has an HPA input port and an HPA output port, second switch device 206 includes an input port, an output port, and a control port, and power combiner device 210 has a first input port, a second input port, and an output port. The input and output ports of the various circuit components of amplifier circuit 200 are indicated by arrows on the signal lines connecting the circuit components in FIG. 2. In the illustrated embodiment, the input port of first switch device 202 is coupled to input port 212A of amplifier circuit 200, the first output port of first switch device 202 is coupled to the HPA input port of HPA device 204, and the HPA output port of HPA device 204 is coupled to the input port of second switch device 206. Also, an output port of the second switch device 206 may be coupled to a first input port of the power combiner device 210, a second output port of the first switch device 202 is coupled to a second input port of the power combiner device 210, and an output port of the power combiner device 210 is coupled to an output port 212B of the amplifier circuit 200.

[0037] In the exemplary amplifier circuit 200, a bandpass filter device 208 allows input signals to pass within a specified frequency range, for example to filter out switching transients. In some cases, the bandpass filter 208 has a center frequency at or near the spin resonance frequency f0 and a bandwidth 4f IFAlternatively, bandpass filter device 208 may have other characteristics (e.g., a larger bandwidth). Bandpass filter device 208 may be located in various locations within example amplifier circuit 200. For example, bandpass filter device 208 may be located between HPA device 204 and second switch device 206. In this case, an input port of bandpass filter device 208 is coupled to an HPA output port of HPA device 204, and an output port of bandpass filter device 208 is coupled to an input port of second switch device 206. For example, bandpass filter device 208 may be located between second switch device 206 and power combiner device 210. In this case, an input port of bandpass filter device 208 is coupled to an output port of second switch device 206, and an output port of bandpass filter device 208 is coupled to a first input port of power combiner device 210. In another example, bandpass filter device 208 may be located between power combiner device 210 and output port 212B. In this case, an input port of the bandpass filter device 208 is coupled to an output port of the power combiner device 210, and an output port of the bandpass filter device 208 is coupled to the output port 212B of the example amplifier circuit 200. In certain cases, the bandpass filter device 208 may be coupled differently to other ones of the components of the amplifier circuit 200.

[0038] In some implementations, the example amplifier circuit 200 includes one or more control ports 214 for receiving control signals. As shown in FIG. 2, the example amplifier circuit 200 includes a first control port 214A connected to the control port of the first switch device 202 and a second control port 214B connected to the control port of the second switch device 206. In some implementations, the example amplifier circuit 200 receives digital control signals at the first and second control ports 214A, 214B, for example, from the signal processing unit 102 of the magnetic resonance system 100 of FIG. 1. For example, each of the digital control signals may be a transistor-to-transistor logic (TTL) signal having two TTL levels. In this case, the digital control signal is a single-bit control signal and has two states. When the TTL signal is in a first state (e.g., a voltage in the range of 1.5 to 5 volts (V)), the TTL logic level is a digital "1" or logic high level. Similarly, when the TTL signal is in a second state (e.g., a voltage in the range of 0 to 0.7 V), the TTL logic level is a digital "0" or logic low level. In some cases, the TTL logic level may be in another range, and the digital control signals received at the first and second control ports 214A and 214B may be other types of digital signals. Depending on the implementation, the switching times of the first and second switch devices 202, 206 that enable switching between pulsed and continuous wave operating modes may be on the nanosecond (ns) timescale, tens of nanoseconds, or other timescales.

[0039] In some implementations, the input and output ports of a switch device may be selectively coupled or decoupled depending on the state of a digital control signal. An input port of a switch device may be considered coupled to an output port of the switch device when the switch device is configured to deliver signals from the input port to the output port with no or negligible attenuation. Similarly, an input port of a switch device may be considered decoupled from an output port of the switch device when the switch device is configured to negligibly transmit signals from the input port to the output port of the switch device. For example, a switch device may completely block a signal or substantially attenuate the signal (at an attenuation level above a threshold). In some cases, the threshold attenuation level of a signal between the input port and output port of the first switch device 202 is 30 dB or greater, and the threshold attenuation level of a signal between the input port and the first or second output port of the second switch device 206 is 50 dB or greater. The switch devices (202, 206) may be implemented with other characteristics (e.g., lower or higher thresholds).

[0040] In some implementations, the first switch device 202 is configured to switch between a first state and a second state in response to a change in state of a first digital control signal at the first control port 214A. When the first digital control signal received at the first switch device 202 is in the first state (e.g., a logic high level), the first switch device 202 is in the first state in which the input port is coupled to the first output port of the first switch device 202. While the first switch device 202 is in the first state, the first switch device 202 delivers the magnetic resonance control signal from the input port to the first output port of the first switch device 202 with no or negligible attenuation. Under the first state of the first switch device 202, the input port is also disconnected from the second output port of the first switch device 202. When the input port is disconnected from the second output port of the first switch device 202, the signal path in the first switch device 202 defined between the input port and the second output port provides sufficient attenuation such that there is negligible transmission of the magnetic resonance control signal on the signal path, resulting in substantially no or negligible output signal at the second output port of the first switch device 202. In this case, the magnetic resonance control signal at the input port 212A of the amplifier circuit 200 is the first magnetic resonance control signal received from the spectrometer circuit at the input port 212A. In some implementations, the first magnetic resonance control signal can be, for example, a high-power microwave pulse of a given frequency v in a constant magnetic field B used for pulsed magnetic resonance measurements.

[0041] Similarly, when the first digital control signal is in a second state (e.g., a logic low level), the first switch device 202 is in a second state that couples the input port to the second output port of the first switch device 202, which allows the magnetic resonance control signal to be delivered from the input port to the second output port of the first switch device 202 with no or negligible attenuation. Under the second state of the first switch device 202, the input port is also disconnected from the first output port of the first switch device 202. When the input port is disconnected from the first output port of the first switch device 202, the signal path in the first switch device 202 defined between the input port and the first output port provides sufficient attenuation such that transmission of the input signal on the signal path is negligible, and substantially there is no or negligible output signal at the first output port of the first switch device 202. In this case, the input signal at the input port 212A of the amplifier circuit 200 is the second magnetic resonance control signal received from the spectrometer unit 104 of the magnetic resonance system 100. In some implementations, the second magnetic resonance control signal may be a microwave irradiation field with a constant frequency v and a sweeping external magnetic field B0 (or a microwave irradiation field with a constant magnetic field B0 and a sweeping frequency v) for continuous wave magnetic resonance measurements.

[0042] Thus, when the first switch device 202 is in the second state, the second magnetic resonance control signal received at the first switch device 202 is transmitted via a path that bypasses the HPA device 204 so that noise from the HPA device 204 does not corrupt the second magnetic resonance control signal. In some implementations, the switching time of the first switch device 202 is in a range of 5 to 20 nanoseconds, 200 nanoseconds or less, 1 microsecond (μsec) or less, or other ranges. In some implementations, the first switch device 202 can receive and handle magnetic resonance control signals having power values ​​up to 1 watt (W) or other ranges.

[0043] In some embodiments, the first switch device 202 has more than one state. For example, the first switch device 202 is switched to a third state in which the input port is coupled to the second output port of the first switch device 202, which allows delivery of a magnetic resonance control signal from the input port to the second output port of the first switch device 202 with no or negligible attenuation. Under the third state of the first switch device 202, the input port is also coupled to the first output port of the first switch device 202 with attenuation (e.g., 40-50 dB or other range). In some embodiments, the attenuated magnetic resonance control signal at the output port of the first switch device 202 may be used in a magnetic resonance system or other process.

[0044] In some implementations, the HPA device 204 receives a magnetic resonance control signal from the first output node of the first switch device 202, amplifies the received magnetic resonance control signal, and transmits the amplified magnetic resonance control signal to the second switch device 206.

[0045] In some implementations, during continuous wave magnetic resonance measurements, the first and second switch devices 202, 206 are in the second state for the same time period (t1-t0) according to the state of the digital control signal received at the control port as defined in the control sequence of Figure 8 A. In some implementations, the second switch device 206 is configured for HPA blanking during pulsed magnetic resonance measurements. For example, during a first period (e.g., t4-t0 in FIG. 8B), when the first digital control signal at the first control input 214A and the second digital control signal at the second control port 214B are both in a first state (e.g., a logical high level), the input port is coupled to the output port of the second switch device 206, and during the first period, an amplified magnetic resonance control signal is delivered from the input port to the output port of the second switch device 206; during a second period (e.g., t4-t1 in FIG. 8B), when the first digital control signal at the first control port 214A remains in the first state and the second digital control signal is switched to a second state (e.g., a logical low level), during the second period, the input port is disconnected from the output port of the second switch device 206, and the amplified magnetic resonance control signal is blanked (e.g., the amplified magnetic resonance control signal at the output port of the second switch device 206 is negligible). In some implementations, the second period may be a dead time (t ) immediately following the first period, as shown in FIG. 8B. dead =t2-t1) and the acquisition time (t acq = t3 - t2). In some implementations, the switching time of the second switch device 206 is in the range of 5 to 20 nanoseconds, 200 nanoseconds or less, 1 microsecond or less, or other ranges. In some implementations, the second switch device 206 can receive and handle input signals of power up to 1 W or other ranges. In some cases, the second switch device 206 can be configurable to handle higher powers, for example, in the range greater than 1 W, up to tens of watts, up to 10 kilowatts (kW), or other ranges, depending on the HPA device 204.

[0046] In some implementations, the first switch device 202 is a single-pole, double-throw switch device, and the second switch device 206 is a single-pole, single-throw switch device. In some cases, each of the first and second switch devices 202, 206 may be another type of switch device. For example, each of the first and second switch devices 202, 206 may have any number of poles, any number of throws, and any number of input ports, output ports, and control ports. In some cases, each of the first and second switch devices 202, 206 may include more than two states. In some cases, the control port of each of the first and second switch devices 202, 206 may interface with a 1-bit control line, a 2-bit control line, or other multi-bit control line for receiving different types of digital control signals.

[0047] In some implementations, the power combiner device 210 combines signals received at a first input port and a second input port of the power combiner device 210 and transmits the combined signal to an output port of the power combiner device 210 (e.g., output port 214B of the exemplary amplifier circuit 200).

[0048] FIG. 3 is a flow diagram illustrating an embodiment of an example process 300. The example process 300 may be performed, for example, to operate an amplifier circuit. For example, the operations in the example process 300 may be performed by operating respective circuit components of the example amplifier circuit 200 shown in FIG. 2 or other amplifier circuits. The example process 300 may include additional or different operations, including operations performed by additional or different components, and the operations may be performed in the order shown in FIG. 3 or in a different order. In some cases, the operations in the example process 300 may be combined, repeated, or otherwise performed repeatedly or in another manner during magnetic resonance measurements.

[0049] In some cases, the operations in the example process 300 shown in FIG. 3 are implemented as a process for providing nanosecond switching between two different operating modes in magnetic resonance measurements, e.g., pulsed mode and continuous wave mode, and for processing the respective magnetic resonance control signals under the different modes before being delivered to the resonator devices in the resonator circuit (e.g., the resonator devices 404, 434, 604, 634 of the resonator circuits 400, 430, 600, 630 of FIGS. 4A-4B and 6A-6B).

[0050] At 302, a signal is received. As shown in Figure 3, operation 302 includes two sub-operations 302A and 302B. At sub-operation 302A, a magnetic resonance control signal is received at input port 212A of amplifier circuit 200, for example, from spectrometer unit 104 of magnetic resonance system 100 of Figure 1. At sub-operation 302B, a digital control signal is received at control ports 214A and 214B of amplifier circuit 200, for example, from signal processing unit 102 of magnetic resonance system 100 of Figure 1.

[0051] At 304, states of circuit components are controlled based on the digital control signal. In some implementations, states of the first and second switch devices 202, 206 in the amplifier circuit 200 are controlled based on states of the received digital control signal. For example, when the received magnetic resonance control signal is for pulsed magnetic resonance measurement and the digital control signal on the first switch device 202 is in a first state (e.g., a logical high level), the switch device 202 of the example amplifier circuit 200 of FIG. 2 is in a first state. When the first switch device 202 is in the first state, the input port 212A is coupled to the first output port of the first switch device 202, which allows delivery of the magnetic resonance control signal from the input port 212A to the first output port of the first switch device 202 with no or negligible attenuation. Under the first state of the first switch device 202, the input port is also disconnected from the second output port of the first switch device 202. In some implementations, the digital control signal applied to the first switch device 202 is a single-bit digital control signal or other type of digital control signal. Also, when the magnetic resonance control signal is a signal for pulsed magnetic resonance measurement, the digital control signal on the second switch device 206 is in a first state (e.g., a logic high level), and the second switch device is in a first state. When the second switch device 206 is in the first state, the input port is coupled to the output port of the second switch device 206 with no or negligible attenuation. In some cases, the second switch device 206 may be switched to the second state for HPA blanking.

[0052] As another example, when the magnetic resonance control signal received by the amplifier circuit 200 is a signal for continuous wave magnetic resonance measurement, the digital control signal received at the control port 214A by the first switch device 202 is in a second state (e.g., a logic low level), and the first switch device 202 is in a second state. When the first switch device 202 is in the second state, the input port 214A is coupled to the second output port of the first switch device 202, which allows delivery of the magnetic resonance control signal from the input port 212A to the second output port of the first switch device 202 with no or negligible attenuation. Under the second state of the first switch device 202, the input port may also be disconnected from the first output port of the first switch device 202. In some cases, when the magnetic resonance control signal is a signal for continuous wave magnetic resonance measurement, the digital control signal received at the control port 214B by the second switch device 206 is in a second state (e.g., a logic low level). When the second switch device 206 is in the second state, the input port is disconnected from the output port of the second switch device 206 .

[0053] At 306, the magnetic resonance control signal is processed based on the state of the circuit components of the amplifier circuit 200. The magnetic resonance control signal can be processed in two subroutines, for example, a first subroutine including operations 310, 312, 314 for processing the magnetic resonance control signal for pulsed magnetic resonance measurements, and a second subroutine 322 including operation 316 for continuous wave magnetic resonance measurements.

[0054] At 310, the first and second switch devices 202, 206 are in a first state, and the magnetic resonance control signal is communicated to the HPA device 204. Specifically, the magnetic resonance control signal is communicated from an input port of the first switch device 202 to a first output port of the first switch device 202, which is coupled to an HPA input port of the HPA device 204. The HPA device 204 is configured to amplify the magnetic resonance control signal. The first subroutine 320 then proceeds to operation 312, where the magnetic resonance control signal is amplified by the HPA device 204, and proceeds to operation 314, where the amplified magnetic resonance control signal is communicated to the power combiner device 210. The second subroutine 322 includes operation 316, where the first and second switch devices 202, 206 are in a second state, and the magnetic resonance control signal is communicated directly from the first switch device 202 to the power combiner device 210, bypassing the HPA device 204.

[0055] At 308, the output of the power combiner device 210 is communicated to a resonator circuit of the magnetic resonance system (eg, resonator circuits 400, 430, 600, 630 of FIGS. 1, 4A, 4B, 6A-6B in the resonator unit 108 of the magnetic resonance system 100).

[0056] In some cases, operations 302, 304, 306, and 308 in the example process 300 are performed as an iterative process, with each iteration including receiving a magnetic resonance control signal and a digital control signal, controlling the state of a circuit component based on the digital control signal, processing the magnetic resonance control signal based on the state of the circuit component, and delivering the magnetic resonance control signal from the power coupling device to the resonator circuit in which the resonator device resides. Each iteration of the iterative process may include additional operations. During each iteration, different subroutines 320 and 322 may be selected based on the state of the circuit component and used to process the magnetic resonance control signal according to the operating mode of the magnetic resonance measurement being performed. Operations 302, 304, 306, and 308 may be repeated in any order, as appropriate, during the same magnetic resonance experiment or several magnetic resonance experiments.

[0057] In some cases, the first and second subroutines 320, 322 may include additional operations. For example, if the amplifier circuit 200 includes a bandpass filter device 208, which may be present in various locations within the amplifier circuit 200, the first subroutine 320 may include operating the bandpass filter device 208 to filter the first magnetic resonance control signal. For example, the amplified first magnetic resonance control signal may be passed through the bandpass filter device 208 before transmitting the amplified first magnetic resonance control signal to the power combiner device 210. If the bandpass filter device 208 is connected between the power combiner device 210 and the output port 212B, the example process 300 may include, after operation 308, an operation in which the output of the power combiner device 210 is filtered by operation of the bandpass filter device 208.

[0058] 4A is a schematic diagram illustrating an embodiment of an example resonator circuit 400 of a magnetic resonance system. In some implementations, the example resonator circuit 400 is deployed as part of a magnetic resonance system, such as the resonator unit 108 of the example magnetic resonance system 100 of FIG. 1 . In some implementations, the example resonator circuit 400 is configured to facilitate integration of a cryogenic low-noise amplifier device into the resonator device and to provide nanoscale switching between a normal operating mode (e.g., pulsed / continuous wave mode) and a pulsed transient digitization / correction mode for magnetic resonance measurements. In some implementations, the example resonator circuit 400 enables sequential acquisition of a pulsed transient field and a spin signal in the same experiment.

[0059] As shown in FIG. 4A , the exemplary resonator circuit 400 includes a first switch device 402, a resonator device 404, a second switch device 406, a bandpass filter device 408, a limiter device 410, and a low-noise amplifier (LNA) device 412. As shown in FIG. 4A , the exemplary resonator circuit 404 is a two-port device including an input port, an output port, and a resonator configured between the input port and the output port. The resonator is configured to operate in a transmission mode, e.g., to receive a signal from the input port and generate an output signal from the output port. The first switch device 402 includes an input port, an output port, and a control port. The second switch device 406 includes an input port, a first output port, a second output port, and a control port. The input port of the first switch device 402 receives a magnetic resonance control signal from an amplifier circuit (e.g., the exemplary amplifier circuit 200 of FIG. 2 or another scheme) at a first port 422A. An input port of the resonator device 404 is coupled to an output port of the first switch device 402. An input port of the second switch device 406 is coupled to an output port of the resonator device 404. The resonator circuit 400 further includes a first control port 424A and a second control port 424B. The control port of the first switch device 402 is coupled to the first control port 424A of the resonator circuit 400, and the control port of the second switch device 406 is coupled to the second control port 424B of the resonator circuit 400. In some cases, the first switch device 402 may be omitted.

[0060] In the exemplary resonator circuit 400, the bandpass filter device 408 and the limiter device 410 each include a respective input port and an output port. As shown in FIG. 4A , the input port of the bandpass filter device 408 is coupled to a first output port of the second switch device 406. The input port of the limiter device 410 is coupled to the output port of the bandpass filter 408. The LNA device 412 includes an LNA input port and an LNA output port. The LNA input port is coupled to the output port of the limiter device 410. The LNA output port is further coupled to a receiver circuit of the magnetic resonance system at a second port 422B. The second output port of the second switch device 406 is coupled to a receiver circuit of the magnetic resonance system at a third port 422C.

[0061] In certain cases, a first output port of the second switch device 406 may be directly coupled to an input port of the limiter device 410 without going through the bandpass filter device 408 (e.g., the bandpass filter device 408 may be omitted). In certain cases, the bandpass filter device 408 may be coupled to other components of the resonator circuit 400 in a different manner. For example, an input port of the bandpass filter device 408 may be coupled to an output port of the resonator device 404, and an output port of the bandpass filter device 408 may be coupled to an input port of the second switch device 406. In this case, a first output port of the second switch device 406 may be directly coupled to an input port of the limiter device 410. Depending on the implementation, the bandpass filter device 408 may be implemented as the bandpass filter device 208 of FIG. 2 or in other manners.

[0062] In FIG. 4A , input and output ports of circuit components of the example resonator circuit 400 are indicated by arrows on the signal connections between the circuit components. In some cases, the signal connections between circuit components of the resonator circuit 400 include waveguides, coaxial cables, metallic wiring or feed lines, or other types of signal lines. In some cases, the example resonator circuit 400 resides in a cryogenic environment at extremely low temperatures where the resonator resides. In some cases, at least a portion of the resonator circuit 400 resides in a different environment than the resonator device 404. For example, the first and second switch devices 402, 406 and the LNA device 412 may reside outside of the cryostat where the resonator circuit device 404 resides, e.g., at room temperature. In some embodiments, the example resonator circuit 400 may include additional or different components, and the components may be arranged as shown or in another manner.

[0063] In some implementations, the state of the first digital control signal at the first control port 424A determines the state of the first switch device 402. For example, when the first digital control signal is in a first state (e.g., a logic high level), the first switch device 402 is in a first state. When the first switch device 402 is in the first state, the input port of the first switch device 402 is coupled to the output of the first switch device 402, thereby allowing the magnetic resonance control signal to be delivered from the input port to the output port of the first switch device 402. When the first digital control signal is in a second state (e.g., a logic low level), the first switch device 402 is in a second state. When the first switch device 402 is in the second state, the input port of the first switch device 402 is disconnected from the output of the first switch device 402, thereby blocking the magnetic resonance control signal from being delivered to the output port of the first switch device 402. In some cases, signal noise from the amplifier circuit 200, for example, at room temperature, may be received at the first port 422A of the resonator circuit 400. The first switch device 404 is configured to isolate and block the signal noise and thermal noise from reaching the resonator device 404 and other portions of the magnetic resonance system during signal acquisition. In some implementations, the first switch device 402 is a single-pole, single-throw (SPST) switch device or other type of switch device controllable by other types of digital control signals. In some implementations, the first switch device 402 may be implemented as the second switch device 206 of the amplifier circuit of FIG. 2 or in another manner.

[0064] In some implementations, the state of the second digital control signal at the second control port 424B determines the state of the second switch device 406. For example, when the second digital control signal is in a first state (e.g., a logic high level), the second switch device 406 is in the first state. When the second switch device 406 is in the first state, the input port of the second switch device 406 is coupled to the first output port of the second switch device 406, thereby allowing the magnetic resonance detection signal received from the output port of the resonator device 404 to be delivered from the input port to the first output port of the second switch device 406. At the same time, when, for example, the attenuation value between the signal levels at the input port and the second output port is greater than 60 dB, the input port is disconnected from the second output port of the second switch device 406. Under the first state of the second switch device 406, the magnetic resonance detection signal from the resonator device 404 is transmitted to a receiver circuit of a magnetic resonance system and can be used for continuous wave or pulsed magnetic resonance measurements.

[0065] When the second digital control signal is in a second state (e.g., a logic low level), the second switch device 406 is in a second state. When the second switch device 406 is in the second state, the input port of the second switch device 406 is coupled to the second output port of the second switch device 406, thereby allowing the magnetic resonance detection signal received from the output port of the resonator device 404 to be delivered to the second output port of the second switch device 406. At the same time, the input port is disconnected from the first output port of the second switch device 406. Under the second state of the second switch device 406, the magnetic resonance detection signal from the resonator device 404 can be transmitted to receiver circuitry of the magnetic resonance system on a path that bypasses the LNA device 412, and the magnetic resonance detection signal can be used to digitize the pulse transient and further to correct or tune the magnetic resonance control signal received at the first port 422A of the resonator circuit 400.

[0066] In some implementations, the second switch device 406 is a single-pole, double-throw (SPDT) switch device. In some implementations, the second switch device 406 may be implemented as the first switch device 202 of the example amplifier circuit 200 of FIG. 2 or in other manners. In some implementations, the first and second switch devices 402, 406 are cryogenic switch devices. In some cases, the output at the third port 422C of the resonator circuit 400 can be attenuated before being further processed by the receiver unit 110 of the magnetic resonance system 100 of FIG. 1. In some cases, the first and second states of the second switch device 406 may be switched between in a controlled manner any number of times during a single experiment. In some implementations, the second switch device 406 is configured to protect the LNA device 412 from high-power pulses (receiver blanking) and to provide bypass of the LNA device 412 for pulse transient digitization. In some cases, the first and second switch devices 402, 406 may be operated according to the control sequence shown in FIGS. 8A-8B.

[0067] In some implementations, when continuous wave magnetic resonance measurements are performed, the first and second digital control signals received at the first and second switch devices 402, 406 are in a first state for the same time period (t1-t0) as shown in FIG. 8A , and when pulsed magnetic resonance measurements are performed, the first switch device 402 is in a first state for a first time period (t1-t0) and a second state for a second time period (t4-t1), and the second switch device 406 is in a second state for a third time period (t acq In some implementations, the first state occurs during a third period t acq is the dead time (t dead=(t2 - t1), and t3 < t4. During the first period (t1 - t0), since the ADC signal remains at a logical high level, the magnetic resonance detection signal received during the first period is collected by the receiver circuit of the magnetic resonance system (e.g., by the receiver unit 110 of the magnetic resonance system 100 and further by the ADC device 128 of the signal processing unit 102 of the magnetic resonance system 100) and used for digitization and correction of the pulse transient.

[0068] In some embodiments, the resonator device 404 may be fabricated on the surface of the resonator chip. The resonator device 404 may include one or more planar microstrip resonators or one or more coplanar waveguide resonators made of a material that superconducts when operating in a cryogenic environment. In some cases, one or more planar microstrip resonators of the resonator device 404, or one or more coplanar waveguide resonators, may include capacitive-coupled microstrip / coplanar waveguide feedlines made of a variable gap, superconducting material, normal conducting material, or superconducting material plated with a normal conducting material. Depending on the implementation form, the resonator device 404 is compatible with standard hardware for converting the coaxial mode transmission line in the probe to a microstrip transmission line or a coplanar waveguide transmission line on the surface of the resonator chip.

[0069] For example, the resonator device 404 has a maximum Q value greater than 10,000, e.g., Q > 10,000, and a mode volume of less than 0.001 cubic millimeters (<0.0001mm 3 ) and as a result, has an absolute spin number sensitivity for a sample size of less than 100 nanoliters (<100 nL) or other ranges, and may include a planar single microstrip niobium (Nb) resonator. For example, the resonator device 404 has a maximum Q value greater than 1000 and less than than 10,000, e.g., 10,000 > Q > 1000, and a mode volume greater than 0.001 cubic millimeters (>0.001mm 3The resonator device 404 may include a planar single microstrip Nb resonator having a mode volume of 100 nL to 1 microliter (μL), resulting in absolute spin number sensitivity for sample sizes in the 100 nL to 1 μL range, e.g., 100 nL to 100 μL. As another example, the planar single microstrip resonator may be made of yttrium barium copper oxide (YBCO) or other high-temperature superconducting material (e.g., 4 K to 80 K). In this case, the resonator device 404 is configured to handle higher power (e.g., >1 W or other range), thereby achieving a higher signal-to-noise ratio (SNR) resulting from faster signal averaging (shorter than T) and larger Raman fields (e.g., >100 MHz or other range).

[0070] The illustrated limiter device 410 is configured to protect the LNA device 412. For example, the limiter device 410 can be configured to pass signals below a specified power level while attenuating or blocking signals above the specified power level. In some cases, the specified power level threshold is selected according to the specifications of the LNA device 412 to prevent damage to the LNA device 412. In some cases, the limiter device 410 may be coupled to other components of the resonator circuit 400 in a different manner. For example, an input port of the limiter device 410 can be coupled to an output port of the resonator device 404, and an output port of the limiter device 410 can be coupled to an input port of the second switch device 406. In this case, a first output port of the second switch device 406 can be directly coupled to an LNA input port of the LNA device 412.

[0071] In some implementations, the LNA device 412 is a cryogenic LNA device that operates in a cryogenic environment. In some cases, the LNA device 412 may operate in other environments, such as at elevated temperature or room temperature. The LNA device 412 can receive and amplify the magnetic resonance detection signal from the first output port of the second switch device 406.

[0072] 4B is a schematic diagram illustrating an embodiment of an example resonator circuit 430 of a magnetic resonance system. In some implementations, the example resonator circuit 430 is deployed as part of a magnetic resonance system, such as the resonator unit of the example magnetic resonance system 100 of FIG. 1. In some implementations, the example resonator circuit 430 provides integration of a resonator device with a cryogenic low-noise amplifier device and is configured for nanoscale switching between a normal operating mode (e.g., pulsed / continuous wave mode) and a pulsed transient digitization / correction mode in magnetic resonance measurements. In some implementations, the example resonator circuit 430 enables sequential acquisition of a pulsed transient field and a spin signal in the same experiment.

[0073] 4B, the example resonator circuit 430 includes a first switch device 432, a circulator device 433, a resonator device 434, and a second switch device 436. The resonator device 434 is a single-port resonator device that includes an input / output port and is configured to operate in a reflective mode, e.g., to receive an input signal at the input / output port and output an output signal through the same input / output port.

[0074] As shown in FIG. 4B , the exemplary resonator circuit 430 further includes a bandpass filter device 438, a limiter device 440, and an LNA device 442. Each of the bandpass filter device 438, the limiter device 440, and the LNA device 442 includes an input port and an output port. The first switch device 432 includes an input port, an output port, and a first control port. The circulator device 433 includes an input port, an input / output port, and an output port. In some cases, the circulator device 433 can be implemented as a single electrically controlled circulator device, a series of interconnected circulator devices having at least one digitally controllable circulator, a digitally controlled directional coupler, or other types of devices. The input port of the first switch device 432 receives a magnetic resonance control signal from an amplifier circuit (e.g., the exemplary amplifier circuit 200 of FIG. 2 or other schemes) via a first port 452A. The output port of the first switch device 432 is coupled to the input port of the circulator device 433. The input / output ports of the resonator device 434 are coupled to the input / output ports of the circulator device. The second switch device 436 includes an input port, a first output port, a second output port, and a second control port. The input port of the second switch device 436 is coupled to the output port of the circulator device 433. The input port of the bandpass filter device 438 is coupled to the first output port of the second switch device 436. The input port of the limiter device 440 is coupled to the output port of the bandpass filter device 438. The LNA device 442 includes an LNA input port and an LNA output port. The LNA input port is coupled to the output port of the limiter device 440. The LNA output port is further coupled to the receiver circuit of the magnetic resonance system at a second port 452B. The second output port of the second switch device 436 is coupled to the receiver circuit of the magnetic resonance system at a third port 452C.The resonator circuit 430 includes a first control port 454 A coupled to the control port of the first switch device 432 and a second control port 454 B coupled to the control port of the second switch device 436 .

[0075] In certain cases, the bandpass filter device 438 is omitted from the resonator circuit 430. In certain other cases, the bandpass filter device 438 may be coupled differently to other components of the resonator device 430. For example, an input port of the bandpass filter device 438 may be coupled to an output port of the first switch device 432, and an output port of the bandpass filter device 438 may be coupled to an input port of the second switch device 436. In this case, a first output port of the second switch device 436 may be directly coupled to an input port of the limiter device 440. Depending on the implementation, the bandpass filter device 438 may be implemented as the bandpass filter device 208 of FIG. 2 or in other manners.

[0076] In some implementations, the first switch device 432, the second switch device 436, the bandpass filter device 438, the limiter device 440, and the LNA device 442 may be implemented as the respective devices in FIG. 4A or in other manners. In some implementations, the input, output, and input / output ports of the example resonator circuit 430 are coupled to one another via waveguides, coaxial cables, metallic wiring or feed lines, or other types of signal lines. In some cases, the first and second switch devices 432, 436, the bandpass filter device 438, the limiter device 440, and the LNA device 442 of the example resonator circuit 430 may reside within the cryogenic environment in which the resonator device 434 resides, or at elevated cryogenic temperatures, or at room temperature. In some embodiments, the example resonator circuit 430 may include additional or different components, and the components may be arranged as shown or in other manners.

[0077] In some implementations, the state of the first digital control signal at the first control port 454A determines the state of the first switch device 432. For example, when the first digital control signal is in a first state (e.g., a logic high level), the first switch device 432 is in a first state. When the first switch device 432 is in the first state, the input port of the first switch device 432 is coupled to the output port of the first switch device 432, thereby allowing the magnetic resonance control signal to be delivered from the input port 452A to the output port of the first switch device 432.

[0078] When the first digital control signal at the first control port 454A is in a second state (e.g., a logic low level), the first switch device 432 is in a second state. When the first switch device 432 is in the second state, the output port of the first switch device 432 is disconnected from the input port of the first switch device 432, thereby preventing the magnetic resonance detection signal from the resonator device 434 from being delivered to the input port of the first switch device 432 and blocking the magnetic resonance control signal or other noise signals from being delivered to the resonator device 434.

[0079] Depending on the implementation, the switching time of the first switch device 432 is 20 nanoseconds or less, 30 nanoseconds or less, or other ranges. In some cases, signal noise from the amplifier circuit 200 at room temperature may be received at the first port 452A of the resonator circuit 430. The first switch device 432 is configured to isolate and block the signal noise from reaching the resonator device 434 and other portions of the magnetic resonance system during signal acquisition.

[0080] In some implementations, the input port of the circulator device 433 is coupled to the input / output port of the circulator device 433 and remains disconnected or isolated from the output port of the circulator device 433, and the output port of the circulator device 433 is coupled to the input / output port of the circulator 433 and remains disconnected or isolated from the input port of the circulator device 433. In some implementations, the circulator device 433 allows a magnetic resonance control signal to be delivered from the first switch device 432 to the resonator device 434 and allows a magnetic resonance detection signal to be delivered from the resonator device 434 to the second switch device 436.

[0081] In some implementations, the state of the second digital control signal at the second control port 454B determines the state of the second switch device 436. For example, when the second digital control signal is in a first state (e.g., a logic high level), the second switch device 436 is in the first state. When the second switch device 436 is in the first state, the input port of the second switch device 436 is coupled to the first output port of the second switch device 436, thereby allowing a signal received from the output port of the circulator device 433 to be delivered to the LNA device 442 via the first output port of the second switch device 436, and the input port is disconnected from the second output port of the second switch device 436. Under the first state of the second switch device 436, the signal is used for continuous wave or pulsed magnetic resonance measurements.

[0082] When the second digital control signal is in a second state (e.g., a logic low level), the second switch device 436 is in a second state. When the second switch device 436 is in the second state, the input port of the second switch device 436 is coupled to the second output port of the second switch device 436, thereby allowing the magnetic resonance detection signal received from the output port of the circulator device 433 to be delivered to the second output port of the second switch device 437, and the input port is disconnected from the first output port of the second switch device 436. Under the second state of the second switch device 436, the magnetic resonance detection signal received from the output port of the first switch device 432 is transmitted via the second output port of the second switch device 436 to a path that bypasses the bandpass filter device 438, the limiter device 440, and the LNA device 442, and the magnetic resonance detection signal is collected by the receiver unit 110 and further by the ADC device 128 of the signal processing unit 102 of the magnetic resonance system 100. In some implementations, the magnetic resonance detection signals are used to digitize the pulse transients, which can be analyzed by a computer system and further used to correct the magnetic resonance control signals generated by the signal processing unit 102.

[0083] In some implementations, when continuous wave magnetic resonance measurements are performed, the first and second switch devices 432, 436 are in a first state for the same time period (t1-t0), as defined by the control sequence shown in FIG. 8A ; when pulsed magnetic resonance measurements are performed, the first switch device 402 is in a first state for a first time period (t1-t0) and a second state for a second time period (t4-t1), and the second switch device 406 is in a second state for a third time period (t acq In some implementations, the control circuit 100 is in the first state during a fourth period (t = t3 - t2) and in the second state during a fourth period (t = t1 - t0 and t = t4 - t3). acq is the dead time (t deadis separated from the first period by (t2 - t1), and t3 < t4. During the first period (t1 - t0), the magnetic resonance measurement is in the digitization / correction mode.

[0084] Depending on the implementation form, the second switch 436 is a single-pole double-throw (SPDT) switch. In some cases, the signal output at the third port 452C of the resonator circuit 430 can be attenuated before being further processed by the receiving circuit of the magnetic resonance system. In some cases, the first state and the second state of the second switch device 436 can be switched any number of times in a controlled manner during a single experiment. Depending on the implementation form, the second switch device 436 protects the LNA device 442 from high-output pulses (receiver blanking) and is configured to realize a bypass of the LNA device 442 where the signal may potentially damage the LNA device 442 for pulse transient digitization. Depending on the implementation form, the second switch device 436 may be implemented as the switch device 406 of the resonator circuit 400 in FIG. 4A or other types of switch devices that can be controlled by other types of digital control signals (e.g., 1-bit, 2-bit or multi-bit digital control signals).

[0085] FIG. 5 is a flowchart showing aspects of an exemplary process 500. In some cases, the exemplary process 500 shown in FIG. 5 is used to switch between the normal operation mode (e.g., continuous wave or pulse mode) and the digitization / correction mode in magnetic resonance measurement with a nanosecond switching time. The exemplary process 500 can be performed, for example, by the operation of a resonator circuit. For example, the operations in the exemplary process 500 may be performed by the exemplary resonator circuits 400, 430 shown in FIGS. 4A - 4B or other types of circuits. The exemplary process 500 may include additional or different operations including operations performed by additional or different components, and the operations may be performed in the order shown or in other orders. In some cases, the operations in the exemplary process 500 can be combined, repeated, or otherwise iterated or performed in another manner during magnetic resonance measurement.

[0086] At 502, a signal is received. As shown in FIG. 5, operation 502 includes two sub-operations 502A and 502B. During sub-operation 502A, a magnetic resonance control signal is received at input ports 422A and 452A of resonator circuits 400 and 430, for example, from the bypass circuit 106 of the magnetic resonance system 100 of FIG. 1. During sub-operation 502B, a digital control signal is received at control ports 424A, 424B, 454A, and 454B of resonator circuits 400 and 430, for example, from the signal processing unit 102 of the magnetic resonance system 100 of FIG. 1. Depending on the implementation, the magnetic resonance control signal may be generated by the signal processing unit 102 and the spectrometer unit 104 of the magnetic resonance system 100 of FIG. 1 or in other manners.

[0087] At 504, the states of the circuit components are controlled based on the digital control signals. In some implementations, the states of the first and second switch devices 402, 406 in the resonator circuit 400 or the states of the first and second switch devices 432, 436 in the resonator circuit 430 are controlled based on the states of the received digital control signals. For example, when the digital control signal received by the first switch device 402, 432 at the control port 424A, 454A is in a first state (e.g., a logic high level), the first switch device 402, 432 is in a first state. When the first switch device 402 is in the first state, the first port 422A is coupled to the output port of the first switch device 402, which allows for delivery of the magnetic resonance control signal from the first port 422A to the output port of the first switch device 402 with no or negligible attenuation. When the digital control signal received by the first switch device 402 at the control port 424A is in a second state (e.g., a logic low level), the first switch device 402 is in a second state in which the input port is disconnected from the output port of the first switch device 402. When the digital control signal received by the first switch device 432 at the control port 454A is in a first state (e.g., a logic high level), the first switch device 432 is in a first state in which the input port 452A is coupled to the input / output port of the circulator device 433, which allows for unattenuated or negligible attenuation of the magnetic resonance control signal to be delivered from the input port 452A to the input / output port of the circulator device 433. In some implementations, the digital control signal applied to the first switch devices 402, 432 is a single-bit digital control signal or another type of digital control signal.

[0088] 4A, 4B is in a first state when a digital control signal received by the second switch device 406, 436 at the control port 424B, 454B is in a first state (e.g., a logic high level). When the second switch device 406, 436 is in the first state, the input port of the second switch device 406, 436 is coupled to the first output port of the second switch device 406, 436, which enables delivery of the magnetic resonance detection signal from the input port to the first output port of the second switch device 406, 436 with no or negligible attenuation. Under the first state of the second switch device 406, 436, the input port is also disconnected from the second output port of the second switch device 406, 436. In some implementations, the second switch device 406, 436 is in a second state when the digital control signal received by the second switch device 406, 436 at the control port 424B, 454B is in a second state (e.g., a logic low level). When the second switch device 406, 436 is in the second state, the input port of the second switch device 406, 436 is coupled to the second output port of the second switch device 406, 436, which allows for unattenuated or negligible attenuation of the magnetic resonance detection signal delivery from the input port to the second output port of the second switch device 406, 436. Under a first state of the second switch device 406, 436, the input port is disconnected from the first output port of the second switch device 406, 436.

[0089] At 506, a magnetic resonance control signal is processed based on the state of the circuit components of the resonator circuits 400, 430. The magnetic resonance control signal can be processed in two subroutines, for example, a first subroutine 410 including operations 520, 522, 524, 526, 528 for performing magnetic resonance measurements, and a second subroutine 512 including operations 530, 532 for digitizing the pulse transient and further correcting or tuning the magnetic resonance control signal.

[0090] At 520 of the first subroutine 510, an electromagnetic field is generated in a sample volume of the resonator device 404, 434. Optionally, when the first switch device 402, 432 is in a first state, a magnetic resonance control signal is received at the resonator device 404, 434 from the first port 422A, 452A of the resonator circuit 500, 430 via the first switch device 402, 432. Optionally, upon receiving the magnetic resonance control signal at the resonator device 404, 434, an electromagnetic field is generated in the sample volume of the magnetic resonance system according to the magnetic resonance control signal and the configuration / characteristics of the resonator device 404, 434.

[0091] At 522 of the first subroutine 510, a magnetic resonance detection signal is acquired. If the resonator device is a two-port resonator device configured to operate in a transmission mode (e.g., resonator device 404 of FIG. 4A), while the first switch device 402 is in a first state, a magnetic resonance control signal is communicated to an input port of the resonator device 404, and a magnetic resonance detection signal is acquired at an output port of the resonator device 404 and further communicated to an input port of the second switch device 406.

[0092] If the resonator device is a single-port resonator device (e.g., resonator device 434 in FIG. 4B ) having input / output ports and configured to operate in a reflection mode, while the first switch device 432 is in a first state, the magnetic resonance control signal is transmitted to the input / output port of the circulator device 433, and the magnetic resonance detection signal is obtained from the output port of the circulator device 433 and further transmitted to the input port of the second switch device 436.

[0093] At 524 of the first subroutine 510, when the second switch device 406, 436 is in a first state, the magnetic resonance detection signal received at the input port of the second switch device 406, 436 is communicated to the first output port of the second switch device 406, 436 and further communicated to the LNA device 412, 442 of the resonator circuit 400, 430. In some cases, communicating the magnetic resonance detection signal from the second switch device 406, 436 to the LNA device 412, 442 may include additional operations, for example, communicating the magnetic resonance detection signal from the second switch device 406, 436 to the LNA device 412, 442 via the bandpass filter device 408, 438 and / or the limiter device 410, 440.

[0094] The first subroutine 510 then proceeds to operation 526, in which the magnetic resonance detection signal is amplified by the LNA devices 412, 442, and operation 528, in which the amplified magnetic resonance detection signal is transmitted to the receiver unit 110b of the magnetic resonance system 100 for continuous wave or pulsed magnetic resonance measurements. In certain cases, the first subroutine 510 may include other operations, and the operations of the first subroutine 510 may be reordered according to the location of the bandpass filter device and the limiter device in the resonator circuit relative to other components of the resonator circuit.

[0095] At 530 of the second subroutine 512, an electromagnetic field is generated in a sample volume of the resonator device 404, 434. Optionally, when the first switch device 402, 432 is in a first state, a magnetic resonance control signal is received at the resonator 404, 434 from the first port 422A, 452A of the resonator circuit 400, 430 via the first switch device 402, 432. Optionally, upon receiving the magnetic resonance control signal at the resonator device 404, 434, an electromagnetic field is generated in the sample volume of the magnetic resonance system according to the magnetic resonance control signal and the configuration / characteristics of the resonator device 404, 434.

[0096] At 532 of the second subroutine 512, a magnetic resonance detection signal is acquired. If the resonator device is a two-port resonator device configured to operate in a transmission mode (e.g., resonator device 404 of FIG. 4A ), while the first switch device 402 is in a first state, the magnetic resonance control signal is communicated to the input port of the resonator device 404, and the magnetic resonance detection signal is acquired at the output port of the resonator device 404 and further communicated to the input port of the second switch device 406.

[0097] If the resonator device is a single-port resonator device (e.g., resonator device 434 in FIG. 4B ) having input / output ports and configured to operate in a reflection mode, while the first switch device 432 is in a first state, the magnetic resonance control signal is transmitted to the input / output port of the circulator device 433, and the magnetic resonance detection signal is obtained from the output port of the circulator device 433 and further transmitted to the input port of the second switch device 436.

[0098] At 534 of the second subroutine 512, while the second switch device 406, 436 is in a second state, the magnetic resonance detection signal is communicated from the second switch device 406, 436 to a receiver unit of the magnetic resonance system (e.g., the receiver unit 110 of the magnetic resonance system 100 shown in FIG. 1). The magnetic resonance detection signal is used to digitize the pulse transient. The results of the digitization process can be used to correct the magnetic resonance control signal for subsequent magnetic resonance measurements.

[0099] In some cases, operations 502, 504, and 506 (and possibly other operations) are performed as an iterative process, with each iteration including receiving a magnetic resonance control signal and a digital control signal, switching the first switch device 402, 432 and the second switch device 406, 436 in the resonator circuit 400, 430 between a first state and a second state in accordance with the digital control signal, generating a magnetic resonance detection signal in accordance with the magnetic resonance control signal, and delivering the magnetic resonance detection signal to receiver circuitry of a magnetic resonance system. Each iteration of the iterative process may include additional operations. During each iteration, different subroutines 510, 512 may be selected based on the state of circuit components and may be used to perform pulsed / transient digitization or spin signal acquisition during continuous wave or pulsed magnetic resonance measurements. Operations 502, 504, and 506 may be repeated in any order, as appropriate, during the same magnetic resonance measurement.

[0100] 6A is a schematic diagram illustrating an embodiment of an example resonator circuit 600 of a magnetic resonance system. In some implementations, the example resonator circuit 600 is deployed as part of a magnetic resonance system, such as the resonator unit 108 of the example magnetic resonance system 100 of FIG. 1 . In some implementations, the example resonator circuit 600 provides integration of a resonator device with a cryogenic low-noise amplifier device and is configured to switch between a normal operating mode (e.g., pulsed / continuous wave mode) and a pulse transient digitization / correction mode for magnetic resonance measurements on a nanosecond time scale. In some implementations, the example resonator circuit 600 enables sequential acquisition of pulse transient fields and spin signals in the same experiment.

[0101] As shown in FIG. 6A , the exemplary resonator circuit 600 includes a first switch device 602, a resonator device 604, and a first switch device 606. The first switch device 602 includes an input port, an output port, and a control port. The second switch device 606 includes a first input port, a second input port, an output port, and a control port. The resonator circuit 600 includes a first control port 624A coupled to the control port of the first switch device 602 and a second control port 624B coupled to the control port of the second switch device 606. The input port of the first switch device 602 receives a magnetic resonance control signal from an amplifier circuit (e.g., the exemplary amplifier circuit 200 of FIG. 2 or other schemes) at a first port 622A. The resonator device 604 has an input port and an output port and is configured to operate in a transmission mode. The input port of the resonator device 604 is coupled to the output port of the first switch device 602. A first input port of the second switch device 606 is coupled to an output port of the resonator device 604 for receiving a magnetic resonance detection signal. The first switch device 602, the resonator device 604, and the second switch device 606 are implemented as respective circuit components of the resonator circuit 400 of FIG. 4A.

[0102] 6A , the resonator device 604 includes an electromagnetic field sensor device 614. A second input port of the second switch device 606 is coupled to the electromagnetic field sensor device 614 to receive a sensor output signal. In some cases, the electromagnetic field sensor device 614 is weakly coupled to the resonator device 604 and is used to monitor transient electromagnetic fields applied to the spins in the sample region. In some implementations, the electromagnetic field sensor device 614 includes a coil device for detecting magnetic fields, a resistor device for detecting electric fields, or another type of electromagnetic field sensor device.

[0103] In the embodiment shown in FIG. 6A , the resonator circuit 600 further includes a bandpass filter device 608, a limiter device 610, and an LNA device 612. Each of the bandpass filter device 608, the limiter device 610, and the LNA device 612 includes an input port and an output port, as indicated by the arrows on the signal connections between the circuit components shown in FIG. 6A . The input port of the bandpass filter device 608 is coupled to the output port of the second switch device 606. The input port of the limiter device 610 is coupled to the output port of the bandpass filter device 608. The LNA device 612 includes an LNA input port and an LNA output port. The LNA input port is coupled to the output port of the limiter device 610. The LNA output port is further coupled to the receiver unit 110 of the magnetic resonance system 100 at a second port 622B of the resonator circuit 600.

[0104] In certain cases, the output port of the bandpass filter device 608 or the second switch device 608 may be directly coupled to the input port of the limiter device 610 without going through the bandpass filter device 608 (e.g., the bandpass filter device 608 may be omitted). In certain cases, the bandpass filter device 608 may be coupled to other circuit components of the resonator circuit 600 in a different manner. For example, the input port of the bandpass filter device 608 may be coupled to the output port of the resonator device 604, and the output port of the bandpass filter device 608 may be coupled to a first input port of the second switch device 606. In this case, the output port of the second switch device 606 may be directly coupled to the input port of the limiter device 610.

[0105] In some implementations, the input and output ports of the components of the example resonator circuit 600 may be connected to each other via waveguides, coaxial cables, metallic wiring or feed lines, or other types of signal lines. In some cases, the first and second switch devices 602, 606, bandpass filter device 608, limiter device 610, and LNA device 612 of the example resonator circuit 600 reside at a cryogenic temperature along with the resonator device 604. In some cases, at least a portion of the resonator device 600 is in a different environment than the resonator device 604. For example, the first and second switch devices 602, 606, and LNA device 612 may reside outside the cryogenic temperature in which the resonator device 604 resides, e.g., at room temperature, or may reside at an elevated cryogenic temperature. In some embodiments, the example resonator circuit 600 may include additional or different components, and the components may be arranged as shown or in other manners.

[0106] Depending on the implementation, the first switch device 602, the resonator device 604, the second switch device 606, the bandpass filter device 608, the limiter device 610, and the LNA device 612 may be implemented as the respective devices of the example resonator circuit 400 of FIG. 4A or in other manners.

[0107] In some implementations, the state of the second digital control signal at the second control port 624B determines the state of the second switch device 606. For example, when the second digital control signal is in a first state (e.g., a logic high level), the second switch device 606 is in the first state. When the second switch device 606 is in the first state, the first input port is coupled to the output port of the second switch device 606, thereby allowing the magnetic resonance detection signal received from the output port of the resonator device 604 to be delivered to the output port of the second switch device 606, and the second input port is disconnected from the output port of the second switch device 606. Under the first state of the second switch device 606, the magnetic resonance detection signal is transmitted to the receiver unit 110 of the magnetic resonance system 100 and used for continuous wave or pulsed magnetic resonance measurements.

[0108] When the second digital control signal is in a second state (e.g., a logic low level), the second switch device 606 is in a second state. When the second switch device 606 is in the second state, the second input port is coupled to the output port of the second switch device 606, thereby allowing a sensor output signal received from the magnetic field sensor device 614 of the resonator device 604 to be delivered from the second input port to the output port of the second switch device 606, and the first input port is disconnected from the output port of the second switch device 606. Under the second state of the second switch device 606, the sensor output signal is communicated to the receiver unit 110 of the magnetic resonance system 100 and used for digitizing the pulse transient and correcting the magnetic resonance control signal.

[0109] In some cases, the signal output at the second port 622B of the resonator circuit 600 may be attenuated before being further processed by the receiver circuitry of the magnetic resonance system. In some cases, the first state and second state of the second switch device 606 may be switched in a controlled manner any number of times during a single experiment to switch between a normal operating mode and a digitization / correction mode.

[0110] 6B is a schematic diagram illustrating an embodiment of an example receiver circuit 630 of a magnetic resonance system. In some implementations, the example resonator circuit 630 is deployed as part of a magnetic resonance system, such as the resonator unit 108 of the example magnetic resonance system 100 of FIG. 1. In some implementations, the example resonator circuit 630 provides integration of a resonator device with a cryogenic low-noise amplifier device and is configured for nanosecond time-scale switching between normal operating modes (e.g., pulsed / continuous wave mode) and pulse transient digitization modes in magnetic resonance measurements. In some implementations, the example resonator circuit 630 enables sequential acquisition of pulse transient fields and spin signals during the same experiment.

[0111] As shown in FIG. 6B , the example resonator circuit 630 includes a first switch device 632, a circulator device 633, a resonator device 634, and a second switch device 636. The example resonator device 634 in FIG. 6B is a single-port resonator device. The resonator device 634 includes input / output ports and is configured to operate in a reflective mode. The example resonator circuit 630 shown in FIG. 6B also includes a bandpass filter device 638, a limiter device 640, and an LNA device 642. The bandpass filter device 638, the limiter device 640, and the LNA device 642 each include a respective input port and an output port, as indicated by arrows on the signal connections between the circuit components of the resonator circuit 630 in FIG. 6B . The first switch device 632 includes an input port, an output port, and a control port. The second switch device 636 includes a first input port, a second input port, an output port, and a control port.

[0112] An input port of the first switch device 632 receives a magnetic resonance control signal from an amplifier circuit (e.g., the exemplary amplifier circuit 200 of FIG. 2 or other schemes) via a first port 652A of the resonator circuit 630. An input port of the circulator device 633 is coupled to an output port of the first switch device 632. An input / output port of the resonator device 634 is coupled to an input / output port of the circulator device 633. A first input port of the second switch device 636 is coupled to the output port of the circulator device 633. The resonator device 634 includes an electromagnetic field sensor device 644. In some cases, the electromagnetic field sensor device 644 is weakly coupled to the resonator device 634 and is used to monitor transient magnetic fields applied to spins of a sample in a sample region of the magnetic resonance system. In some implementations, the electromagnetic field sensor device 644 includes a coil device for sensing magnetic fields, a resistor device for sensing electric fields, or another type of electromagnetic field sensor device. In certain cases, the electromagnetic field sensor device 644 may be implemented as the electromagnetic field sensor device 614 of FIG. 6A or in other manners. The second input port of the second switch device 636 is coupled to the electromagnetic field sensor device 644.

[0113] 6B, an input port of the bandpass filter device 638 is coupled to an output port of the second switch device 636. An input port of the limiter device 640 is coupled to an output port of the bandpass filter device 638. The LNA device 642 includes an LNA input port and an LNA output port. The LNA input port is coupled to the output port of the limiter device 640. The LNA output port is further coupled to the receiver circuit 110 of the magnetic resonance system 100 at a second port 652B of the resonator circuit 630. The resonator circuit 630 further includes a first control port 654A coupled to the control port of the first switch device 632 and a second control port 654B coupled to the control port of the second switch device 636.

[0114] In certain cases, the bandpass filter device 638 may be omitted. For example, an output port of the second switch device 636 may be directly coupled to an input port of the limiter device 640 without going through the bandpass filter device 638. In certain cases, the bandpass filter device 638 may be coupled to other circuit components of the resonator circuit 630 in a different manner. For example, an input port of the bandpass filter device 638 may be coupled to an output port of the first switch device 632, and an output port of the bandpass filter device 638 may be coupled to a first input port of the second switch device 636. In this case, an output port of the second switch device 636 may be directly coupled to an input port of the limiter device 640.

[0115] In some implementations, the input ports, input / output ports, and output ports of the components of the example resonator circuit 630 are connected to each other via waveguides, coaxial cables, metallic wiring or feed lines, or other types of signal lines. In some cases, the first and second switch devices 632, 636, bandpass filter device 638, limiter device 640, and LNA device 642 of the example resonator circuit 630 are in a cryogenic environment or at room temperature. In some implementations, the first switch device 632, resonator device 634, second switch device 636, bandpass filter device 638, limiter device 640, and LNA device 642 may be implemented as the respective devices in the example resonator circuit 430 of FIG. 4B or in other manners. In some embodiments, the example resonator circuit 630 may include additional or different components, and the components may be arranged as shown or in other manners.

[0116] In some implementations, the state of the first digital control signal at the first control port 654A determines the state of the first switch 632. For example, when the first digital control signal is in a first state (e.g., a logic high level), the first switch device 632 is in a first state. When the first switch device 632 is in the first state, the input port is coupled to the output port of the first switch device 632, thereby allowing the magnetic resonance control signal to be delivered from the input port 652A to the output port of the first switch device 632. When the first control digital signal at the first control port 654A is in a second state (e.g., a logic low level), the first switch device 632 is in a second state. When the first switch 632 is in the second state, the input port is disconnected from the input / output port of the first switch device 632, thereby blocking the magnetic resonance control signal from being delivered from the input port 652A to the output port of the first switch device 632.

[0117] Depending on the implementation, the switching time of the first switch device 632 may be 20 nanoseconds or less, 30 nanoseconds or less, or other ranges. In some cases, signal noise from the amplifier circuit 200 at room temperature may be received at the first port 652A of the resonator circuit 630. The first switch device 632 isolates and blocks the signal noise from reaching the resonator device 634 and other components of the magnetic resonance system during signal acquisition.

[0118] In some implementations, the input port of the circulator device 633 is coupled to the input / output port of the circulator device 633 and remains disconnected or isolated from the output port of the circulator device 633, and the output port of the circulator device 633 is coupled to the input / output port of the circulator device 633 and remains disconnected or isolated from the input port of the circulator device 633. In some implementations, the circulator device 633 allows a magnetic resonance control signal to be delivered from the first switch device 632 to the resonator device 634 and allows a magnetic resonance detection signal to be delivered from the resonator device 634 to the second switch device 636.

[0119] In some implementations, the state of the second digital control signal at the second control port 654B determines the state of the second switch device 636. For example, when the second digital control signal is in a first state (e.g., a logic high level), the second switch device 636 is in a first state. When the second switch device 636 is in the first state, the first input port is coupled to the output port of the second switch device 636, thereby allowing the magnetic resonance detection signal received from the output port of the first switch device 632 to be delivered to the LNA device 642 via the output port of the second switch device 636, and the second input port is disconnected from the output port of the second switch device 636. Under the first state of the second switch device 606, the magnetic resonance detection signal is used for continuous wave or pulsed magnetic resonance measurements.

[0120] When the second digital control signal is in a second state (e.g., a logic low level), the second switch device 636 is in a second state. When the second switch device 636 is in the second state, the second input port is coupled to the output port of the second switch device 636, thereby allowing the sensor output signal received from the electromagnetic field sensor device 644 of the resonator device 634 to be delivered from the second input port to the LNA device 642 via the output port of the second switch device 636, and the first input port is disconnected from the output port of the second switch device 636.

[0121] In some implementations, the second switch 636 is a single-pole, double-throw (SPDT) switch device having two positions for delivering signals from different input ports to the same output port of the second switch device 636. In some cases, the first and second switch devices 632, 636 may be other types of switch devices controllable by other types of digital control signals. In some cases, the signal output at the second port 652B of the resonator circuit 630 may be attenuated before being further processed by the receiver unit 110 of the magnetic resonance system 100. In some cases, the first and second states of the second switch device 636 may be switched in a controlled manner any number of times during a single experiment.

[0122] FIG. 7 is a flow diagram illustrating an embodiment of an example process 700. In some cases, the operations in the example process 700 shown in FIG. 7 are implemented as a process for switching between a normal operating mode (e.g., continuous wave or pulsed mode) and a digitization / correction mode in a magnetic resonance measurement with a nanosecond switching time. The example process 700 may be performed, for example, by operation of a resonator circuit. For example, the operations in the example process 700 may be performed by any of the example resonator circuits 600, 630 shown in FIGS. 6A-6B or other types of circuits. The example process 700 may include additional or different operations, including operations performed by additional or different components, and the operations may be performed in the illustrated order or in other orders. In some cases, the operations in the example process 700 may be repeated, combined, iterative, or otherwise, or performed in other manners during a magnetic resonance measurement.

[0123] At 702, a signal is received. As shown in FIG. 7, operation 702 includes two sub-operations 702A and 702B. During sub-operation 702A, a magnetic resonance control signal is received at a first port 622A, 652A of a resonator circuit 600, 630, e.g., as part of the resonator unit 108 of the magnetic resonance system 100 of FIG. 1 . Depending on the implementation, the magnetic resonance control signal may be generated by the signal processing unit 102 and the spectrometer unit 104 of the magnetic resonance system 100 of FIG. 1 , or in other manners. During sub-operation 702B, a digital control signal is received at a control port 624A, 624B, 654A, 654B of the resonator circuit 600, 630, e.g., from the signal processing unit 102 of the magnetic resonance system 100 of FIG. 1 .

[0124] At 704, states of circuit components are controlled based on the digital control signals. In some implementations, the states of the first and second switch devices 602, 606 in the resonator circuit 600 and the states of the first and second switch devices 632, 636 in the resonator circuit 630 are controlled based on the states of the digital control signals received at the control ports 624A, 624B, 654A, 654B. Specifically, when the digital control signal received at the control port 624A by the first switch device 602 is in a first state (e.g., a logic high level), the first switch device 602 of the example resonator circuit 600 of FIG. 6A is in a first state and the first port 622A is coupled to the output port of the first switch device 602, which allows for delivery of the magnetic resonance control signal from the first port 622A to the output port of the first switch device 602 with negligible attenuation. When the digital control signal received by the first switch device 602 at its control port 624A is in a second state (e.g., a logic low level), the first switch device 602 is in a second state in which the first port 622A is disconnected from the output port of the first switch device 602. When the digital control signal received by the first switch device 632 at its control port 654A is in a first state (e.g., a logic high level), the first switch 632 is in a first state in which the first port 652A is coupled to the input / output port of the circulator device 633, which allows for unattenuated or negligible attenuation of the magnetic resonance control signal to be delivered from the input port 652A to the input port of the circulator device 633. In some cases, the digital control signal received by the first switch devices 602, 632 is a single-bit digital control signal or other type of control signal.

[0125] 6A, 6B is in a first state and the input port of the second switch device 606, 636 is coupled to the first output port of the second switch device 606, 636, which enables negligible or no attenuation of the magnetic resonance detection signal delivery from the input port to the first output port of the second switch device 606, 636. Under the first state of the second switch device 606, 636, the input port is disconnected from the second output port of the second switch device 606, 636. 6A, 6B is in a second state when the digital control signal received by the second switch device 606, 636 at the control port 624B, 654B is in a second state (e.g., a logic low level). When the second switch device 606, 636 is in the second state, the input port of the second switch device 606, 636 is coupled to the second output port of the second switch device 606, 636, which enables delivery of the sensor output signal from the input port to the second output port of the second switch device 606, 636 with no or negligible attenuation. Under the second state of the second switch device 606, 636, the input port is disconnected from the first output port of the second switch device 606, 636.

[0126] At 706, the magnetic resonance control signal is processed based on the state of the circuit components of the resonator circuits 600, 630. The magnetic resonance control signal may be processed in two subroutines, for example, a first subroutine 710 including operations 720, 722, 724, 726, 728 for performing a normal mode of operation in magnetic resonance measurements, and a second subroutine 712 including operations 730, 732, 734, 736, 738 for digitizing the pulse transient and further correcting or tuning the magnetic resonance control signal.

[0127] At 720 of the first subroutine 710, an electromagnetic field is generated in a sample volume of the resonator device 704, 734. Optionally, when the first switch device 602, 632 is in a first state, a magnetic resonance control signal is received at the resonator device 604, 632 from the first port 622A, 652A of the resonator circuit 600, 630 via the first switch device 602, 632. Optionally, upon receiving the magnetic resonance control signal at the resonator device 704, 734, an electromagnetic field is generated in the sample volume of the magnetic resonance system according to the magnetic resonance control signal and the configuration / characteristics of the resonator device 704, 734.

[0128] At 722 of the first subroutine 710, a magnetic resonance detection signal is obtained. If the resonator device is a two-port resonator device configured to operate in a transmission mode (e.g., the resonator device of FIG. 6A ), while the first switch device 602 is in a first state, the magnetic resonance control signal is communicated to the input port of the resonator device 604, and the magnetic resonance detection signal is communicated via the output port of the resonator device 604 to a first input port of the second switch device 606.

[0129] If the resonator device is a single-port resonator device (e.g., resonator device 634 in FIG. 6B ) having input / output ports and configured to operate in a reflection mode, while the first switch device 632 is in a first state, the magnetic resonance control signal is transmitted to the input / output port of the resonator device 634 via the circulator device 633, and the magnetic resonance detection signal is obtained from the output port of the circulator device 633 and further transmitted to the first input port of the second switch device 636.

[0130] At 724 of the first subroutine 710, when the second switch device 606, 636 is in a first state, the magnetic resonance detection signal received at the first input port of the second switch device 606, 636 is communicated from the first input port to an output port of the second switch device 606, 636 and further communicated to the LNA device 612, 642 of the resonator circuit 600, 630. In some cases, operation 724 may include additional sub-operations, such as communicating the magnetic resonance detection signal from the second switch device 606, 636 to the LNA device 612, 642 via the bandpass filter device 608, 638 and / or the limiter device 610, 640.

[0131] The first subroutine 710 continues with operation 726, in which the magnetic resonance detection signal is amplified by the LNA devices 612, 642, and operation 728, in which the amplified magnetic resonance detection signal is transmitted to the receiver unit 110 of the magnetic resonance system 100 for continuous wave or pulsed magnetic resonance measurements. In certain cases, the first subroutine 710 may include other operations, and the operations of the first subroutine 710 may be reordered according to the location of the bandpass filter devices and limiter devices in the resonator circuits 600, 630 relative to other circuit components of the resonator circuits 600, 630.

[0132] At 730 of the second subroutine 712, an electromagnetic field is generated in a sample volume of the resonator device 604, 634. Optionally, when the first switch device 602, 632 is in a first state, a magnetic resonance control signal is received at the resonator device 604, 634 from the first port 622A, 652A of the resonator circuit 600, 630 via the switch device 602, 632. Optionally, upon receiving the magnetic resonance control signal at the resonator device 604, 634, an electromagnetic field is generated in the sample volume of the magnetic resonance system according to the magnetic resonance control signal and the configuration / characteristics of the resonator device 604, 634.

[0133] In step 732 of the second subroutine 712, a sensor output signal is obtained. The sensor output signal is obtained from the electromagnetic field sensor device 614, 644 and further communicated to a second input port of the switch device 606, 636. The sensor output signal can be generated in 730 by direct interaction of the electromagnetic field sensor device 614, 644 with the electromagnetic field generated by the resonator device.

[0134] At 734 of the second subroutine 712, when the second switch device 606, 636 is in a second state, the sensor output signal received at the second input port of the second switch device 606, 636 is communicated to the output port of the second switch device 606, 636 and further communicated to the LNA device 612, 642 of the resonator circuit 600, 630. In some cases, operation 724 may include additional sub-operations, such as communicating the sensor output signal from the second switch device 606, 636 to the LNA device 612, 642 via the bandpass filter device 608, 638 and / or the limiter device 610, 640.

[0135] The second subroutine 712 continues with operation 736, in which the sensor output signal is amplified by the LNA devices 612, 642, and operation 738, in which the amplified sensor output signal is transmitted to a receiver unit of the magnetic resonance system for digitization of the pulse transient. The results of the digitization process can be used to correct the magnetic resonance control signal for subsequent magnetic resonance measurements. In certain cases, the second subroutine 712 may include other operations, and the operations of the second subroutine 712 may be reordered according to the location of the bandpass filter devices and limiter devices in the resonator circuits 600, 630 relative to other circuit components of the resonator circuits 600, 630.

[0136] In some cases, operations 702, 704, and 706 (and possibly other operations) are performed as an iterative process, with each iteration including receiving a magnetic resonance control signal and a digital control signal, switching the first switch device 602, 632 and the second switch device 606, 636 in the resonator circuit 600, 630 between a first state and a second state in accordance with the digital control signal, generating a magnetic resonance detection signal and a sensor output signal in accordance with the magnetic resonance control signal, and delivering the magnetic resonance detection signal and the sensor output signal to a receiver unit of a magnetic resonance system. Each iteration of the iterative process may include additional operations. During each iteration, a different subroutine 710, 712 may be selected based on the state of the circuit components and may be used to perform pulsed / transient digitization or spin signal acquisition during continuous wave or pulsed magnetic resonance measurements. Operations 702, 704, and 706 may be repeated in any order as appropriate during the same resonance measurement.

[0137] 8A-8B are timing diagrams 800, 820 illustrating aspects of example control sequences. The control sequences illustrate the states of example control signals received by switch devices at the respective control ports of amplifier circuit 200, as shown in FIG. 2, and resonator circuits 400, 430, 600, 630, as shown in FIGS. 4A-4B and 6A-6B. In some cases, the control sequences are applied during operation of example processes 300, 500, 700, or other processes. In FIGS. 8A-8B, t p represents the length of a given pulse, and t p +t s represents the duration of a given pulse plus the switching time, and t dead represents the spectrometer dead time, and t acqrepresents the acquisition time of the spin signal. In some implementations, timing diagram 800 shown in FIG. 8A is configured to perform magnetic resonance measurements in continuous wave mode, and timing diagram 820 shown in FIG. 8B is used to perform magnetic resonance measurements in pulse mode. In some cases, timing diagrams 800, 820 may be selected and augmented with each other to form a pulse program capable of performing different modes of magnetic resonance measurements in a single experiment or several experiments. In other words, a control sequence may be executed sequentially or repeatedly according to the timing diagrams in the pulse program so that different modes of magnetic resonance measurements can be switched and performed appropriately.

[0138] Portions of the subject matter and operations described herein can be implemented in digital electronic circuitry, or in software, firmware, or hardware, including the structures disclosed herein and their structural equivalents, or in a combination of one or more of these. Portions of the subject matter disclosed herein can be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a computer storage medium for execution by or to control the operation of a data processing apparatus. The computer storage medium can be or be included in a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination of one or more of these. Also, a computer storage medium is not a propagated signal; a computer storage medium can be a source or destination for computer program instructions encoded in an artificially generated propagated signal. A computer storage medium can be or be included in one or more separate physical components or media.

[0139] Some of the operations described herein may be implemented as operations performed by a data processing apparatus on data stored on one or more computer-readable storage devices or received from other sources.

[0140] In a general aspect of the above, a magnetic resonance system is operated.

[0141] In a first embodiment, an amplifier circuit for a magnetic resonance system includes a first switch device, a high power amplifier (HPA) device, a second switch device, and a power combiner device. The first switch device includes an input port, a first output port, a second output port, and a control port. The input port of the first switch device is configured to receive a magnetic resonance control signal. The control port of the first switch device is configured to receive a first digital control signal. The first switch device is configured to selectively couple the input port of the first switch device to the first output port or the second output port of the first switch device based on the state of the first digital control signal. The HPA device includes an HPA input port and an HPA output port. The HPA input port is coupled to the first output port of the first switch device. The second switch device includes an input port, an output port, and a control port. The control port of the second switch device is configured to receive the second digital control signal. The second switch device is configured to selectively couple the input port of the second switch device to the output port of the second switch device based on a state of the second digital control signal. The power combiner device includes a first input port, a second input port, and an output port. The first input port of the power combiner device is coupled to the output port of the second switch device. The second input port of the power combiner device is coupled to the second output port of the first switch device along a path that bypasses the HPA device. The output port of the power combiner device is configured to be coupled to a resonator circuit of a magnetic resonance system.

[0142] Implementations of the first example may include one or more of the following features: the amplifier circuit is configured to operate at room temperature and the resonator circuit is configured to operate at cryogenic temperatures; the amplifier circuit is configured to operate at room temperature and at least a portion of the resonator circuit is configured to operate at room temperature; the amplifier circuit includes a bandpass filter device coupled between the HPA output port and a first input port of the coupler device; the first switch device is configured to switch between a first state and a second state in response to a change in state of a first digital control signal; the first state includes the input port of the first switch device being coupled to the first output port of the first switch device and disconnected from the second output port of the first switch device; the second state includes the input port of the first switch device being coupled to the second output port of the first switch device and disconnected from the first output port of the first switch device; the switching time of the first switch device is 1 μsec or less; and the second switch device is configured to switch between the first state and the second state in response to a change in state of a second digital control signal. The first state includes the input port of the second switch device being coupled to the output port of the second switch device, the second state includes the input port of the second switch device being disconnected from the output port of the second switch device, and the switching time of the second switch device is 1 μs or less.

[0143] In a second embodiment, an amplifier circuit in a magnetic resonance system includes a first switch device, a high power amplifier (HPA) device, a second switch device, and a power combiner device, and a method of operating the amplifier circuit includes receiving a first magnetic resonance control signal at the first switch device while the first switch device is in a first state, communicating the first magnetic resonance control signal from the first switch device to the HPA device, amplifying the first magnetic resonance control signal by operating the HPA device, receiving the amplified magnetic resonance control signal from the HPA device at the second switch device, communicating the amplified magnetic resonance control signal to the power combiner device via the second switch device, and providing a first output of the power combiner device to a resonator circuit of the magnetic resonance system; switching the first switch device from a first state to a second state in response to a digital control signal received by the first switch device; receiving a second magnetic resonance control signal at the first switch device while the first switch device is in the second state; communicating the second magnetic resonance control signal from the first switch device to a power combiner device, wherein communicating the second magnetic resonance control signal from the first switch device to the power combiner device bypasses the HPA; and providing the second output of the power combiner device to the resonator circuit of the magnetic resonance system.

[0144] Implementations of the second example may include one or more of the following features: the amplifier circuit operates at room temperature; the resonator circuit operates at cryogenic temperatures; the amplifier circuit is configured to operate at room temperature, and at least a portion of the resonator circuit is configured to operate at room temperature; and communicating the amplified magnetic resonance control signal to the power combiner device via the second switch device includes communicating the amplified magnetic resonance control signal to the power combiner device through a bandpass filter device.

[0145] In a third embodiment, a resonator circuit is configured to operate in a cryogenic environment of a magnetic resonance system. The resonator circuit includes a resonator device and a low noise amplifier (LNA) device. The resonator device includes an input port, an output port, and a resonator coupled between the input port and the output port. The input port of the resonator device is configured to receive a magnetic resonance control signal. The resonator device is configured to generate an electromagnetic field in a sample volume of the magnetic resonance system in response to the magnetic resonance control signal. The LNA device includes an LNA input port and an LNA output port. The LNA input port is coupled to the output port of the resonator device. The LNA output port is configured to be coupled to receiver circuitry of the magnetic resonance system.

[0146] Implementations of the third example may include one or more of the following features: the amplifier circuit includes a switch device coupled between an output port of a resonator device and an LNA input port; the switch device includes an input port, a first output port, and a second output port; the resonator circuit includes a limiter device coupled between the first output port of the switch device and the LNA input port; the limiter device includes an input port and an output port; the resonator circuit includes a bandpass filter coupled between the first output port of the switch device and the input port of the limiter device; the switch device includes a control port configured to receive a digital control signal; the switch device is configured to switch between a first state and a second state in response to a change in state of the digital control signal; the first state includes the input port of the switch device being coupled to the first output port of the switch device and disconnected from the second output port of the switch device; and the second state includes the input port of the switch device being coupled to the second output port of the device and disconnected from the first output port of the switch device.

[0147] Implementations of the third example may include one or more of the following features: the amplifier circuit includes a switch device; the switch device includes an input port and an output port; the output port of the switch device is coupled to the input port of the resonator device, the input port of the switch device being configured to receive a magnetic resonance control signal; the switch device includes a control port configured to receive a digital control signal; the switch device is configured to switch between a first state and a second state in response to a change in state of the digital control signal; the first state includes the input port of the switch device being coupled to the output of the switch device; and the second state includes the input port of the switch device being disconnected from the output port of the switch device; and the switching time of the switch device is 30 nanoseconds or less.

[0148] In a fourth embodiment, a resonator circuit in a magnetic resonance system includes a resonator device and a low-noise amplifier (LNA) device. The resonator device includes an input port, an output port, and a resonator coupled between the input port and the output port. A method of operating the resonator circuit includes receiving a magnetic resonance control signal at the input port of the resonator device, operating the resonator device to generate an electromagnetic field in a sample volume of the magnetic resonance system in response to the magnetic resonance control signal, operating the resonator device to obtain a magnetic resonance detection signal based on an interaction between the resonator device and the sample in the sample volume, providing the magnetic resonance detection signal from the output port of the resonator device to the LNA device, operating the LNA device to amplify the magnetic resonance detection signal, and providing the amplified magnetic resonance detection signal to a receiver circuit of the magnetic resonance system.

[0149] Implementations of the fourth example may include one or more of the following features: the resonator circuit includes a switch device; the method includes receiving a magnetic resonance detection signal at the switch device from an output port of the resonator device while the switch device is in a first state and communicating the magnetic resonance detection signal from the switch device to an LNA device; the method includes communicating the magnetic resonance detection signal from the switch device to a limiter device coupled between the switch device and the LNA device before amplifying the magnetic resonance detection signal; the method includes switching the switch device from the first state to a second state in response to a digital control signal received by the switch device; receiving the magnetic resonance detection signal at the switch device from the output port of the resonator device while the switch device is in the second state; and communicating the magnetic resonance detection signal from the switch device along a path that bypasses the LNA device.

[0150] Implementations of the fourth example may include one or more of the following features: the resonator circuit includes a switch device; the switch device has a switching time of 30 nanoseconds or less; and the method includes receiving a magnetic resonance control signal at the switch device while the switch device is in a first state before receiving a magnetic resonance control signal at the input port of the resonator device; and communicating the magnetic resonance control signal from the switch device to the input port of the resonator device.

[0151] In a fifth embodiment, a resonator circuit is configured to operate in a cryogenic environment of a magnetic resonance system. The resonator circuit includes a resonator device, a switch device, and a low-noise amplifier (LNA) device. The resonator device includes a resonator configured to generate an electromagnetic field in a sample volume of the magnetic resonance system in response to a magnetic resonance control signal received by the resonator device. The switch device includes an input port, a first output port, a second output port, and a control port. The input port of the switch device is coupled to the resonator device. The control port of the switch device is configured to receive the digital control signal. The switch device is configured to selectively couple the input port of the switch device to the first output port or the second output port of the switch device based on the state of the digital control signal. The second output port of the switch device is configured to be coupled to a receiver circuit of the magnetic resonance system along a path that bypasses the low-noise amplifier (LNA) device. The LNA device includes an LNA input port and an LNA output port. The LNA input port is coupled to the first output port of the switch device. The LNA output port is configured to be coupled to the receiver circuit of the magnetic resonance system.

[0152] Implementations of the fifth example may include one or more of the following features: the resonator circuit includes a limiter device coupled between a first output port of the switch device and an LNA input port; the limiter device includes an input port and an output port; the resonator circuit includes a bandpass filter coupled between the first output port of the switch device and an input port of the limiter device; the switch device is configured to switch between a first state and a second state in response to a change in state of the digital control signal; the first state includes the input port of the switch device being coupled to the first output port of the switch device and disconnected from the second output port of the switch device; and the second state includes the input port of the switch device being coupled to the second output port of the switch device and disconnected from the first output port of the switch device.

[0153] Implementations of the fifth example may include one or more of the following features: the resonator device includes an input port and an output port; the resonator device is configured to operate in a transmission mode; the first input port of the switch device is coupled to the output port of the resonator device; the switch device is a first switch device; the resonator circuit includes a second switch device; the second switch device includes an input port and an output port; the output port of the second switch device is coupled to the input port of the resonator device, and the input port of the second switch device is configured to receive a magnetic resonance control signal.

[0154] Implementations of the fifth example may include one or more of the following features: the digital control signal on the first switch device is a first digital control signal; the second switch device includes a control port configured to receive the second digital control signal and configured to switch between a first state and a second state in response to a change in state of the second digital control signal; the first state includes an input port of the second switch device being coupled to an output port of the second switch device; and the second state includes an input port of the second switch device being disconnected from the output port of the second switch device. The switching time of the second switch device is 30 nanoseconds or less.

[0155] Implementations of the fifth example may include one or more of the following features: a resonator device includes an input / output port and is configured to operate in a reflective mode; an input port of a switch device is coupled to the input / output port of the resonator device; the switch device is a first switch device; the resonator circuit includes a circulator device and a second switch device; the circulator device includes an input port, an input / output port coupled to the input / output port of the resonator device, and an output port coupled to the first input port of the first switch device; and the second switch device includes an input port configured to receive a magnetic resonance control signal and an output port coupled to the input port of the circulator device.

[0156] In a sixth embodiment, a method of operating a resonator circuit in a magnetic resonance system includes a resonator device, a switch device, and a low noise amplifier (LNA) device, the method including receiving a first magnetic resonance control signal at the resonator device while the switch device is in a first state, generating a first electromagnetic field in a sample volume of the magnetic resonance system in response to the first magnetic resonance control signal by operating the resonator, obtaining a first magnetic resonance detection signal by operating the resonator device based on an interaction between the resonator and a sample in the sample volume, communicating the first magnetic resonance detection signal via the switch device to the LNA device, amplifying the magnetic resonance detection signal by operating the LNA device, and communicating the amplified output to a receiver circuit of the magnetic resonance system. switching the switch device from a first state to a second state in response to a digital control signal received at the switch device; receiving a second magnetic resonance control signal at the resonator device while the switch device is in the second state; generating a second electromagnetic field in a sample volume of the magnetic resonance system in response to the second magnetic resonance control signal by operating the resonator device; obtaining a second magnetic resonance detection signal by operating the resonator device based on an interaction between the resonator and the sample; and transmitting the second magnetic resonance detection signal to a receiver circuit via the switch device along a path that bypasses the LNA device.

[0157] Implementations of the sixth example may include one or more of the following features: the resonator circuit includes a limiter device; communicating the first magnetic resonance detection signal to the LNA device through the switch device includes receiving the first magnetic resonance detection signal at the limiter device from the switch device and communicating the first magnetic resonance detection signal from the limiter device to the LNA device; the resonator circuit includes a bandpass filter device; communicating the first magnetic resonance detection signal to the LNA device through the switch device includes receiving the first magnetic resonance detection signal at the bandpass filter device from the switch device and communicating the first magnetic resonance detection signal from the bandpass filter device to the limiter device.

[0158] Implementations of the sixth example may include one or more of the following features: the resonator device includes an input port and an output port; the resonator device is configured to operate in a transmission mode; communicating the first magnetic resonance detection signal through the switch device to the LNA device includes communicating the first magnetic resonance detection signal from the output port of the resonator device to the LNA device through the switch device; and communicating the second magnetic resonance detection signal through the switch device to the receiver circuit along a path that bypasses the LNA device includes communicating the second magnetic resonance detection signal from the output port of the resonator device to the receiver circuit along a path that bypasses the LNA device.

[0159] Implementations of the sixth example embodiment may include one or more of the following features: the switch device is a first switch device, and the resonator circuit includes a second switch device, the second switch device having a switching time of 30 nanoseconds or less, and the method includes receiving a first or second magnetic resonance control signal at the second switch device and communicating the first or second magnetic resonance control signal from the second switch device to an input port of the resonator device.

[0160] Implementations of the sixth example may include one or more of the following features: the resonator device includes an input / output port and is configured to operate in a reflection mode; communicating the first magnetic resonance detection signal to the LNA device through the switch device includes communicating the first magnetic resonance detection signal from the input / output port of the resonator device to the LNA device through the switch device; communicating the second magnetic resonance detection signal to the receiver circuit along a path that bypasses the LNA device through the switch device includes communicating the second magnetic resonance detection signal from the input / output port of the resonator device to the receiver circuit along a path that bypasses the LNA device; the switch device is the first switch device; the resonator circuit includes a circulator device and a second switch device; the circulator device includes an input port, an input / output port, and an output port; and the second switch device includes an input port and an output port. The method includes receiving a first or second magnetic resonance control signal at an input port of the second switch device while the second switch device is in a first state, communicating the first or second magnetic resonance control signal from the input port of the second switch device to an output port of the second switch device, communicating the first or second magnetic resonance control signal from the input port of the circulator device through the input / output port of the circulator device to an input / output port of the resonator device, receiving a first or second magnetic resonance detection signal from the input / output port of the resonator device at the input / output port of the circulator device, and communicating the first or second magnetic resonance detection signal from the input / output port of the circulator device through the output port of the circulator device to the first switch device.

[0161] In a seventh embodiment, a resonator circuit is configured to operate in a cryogenic environment of a magnetic resonance system. The resonator circuit includes a resonator device, an electromagnetic field sensor device, and a switch device. The resonator device includes a resonator configured to generate an electromagnetic field in a sample volume of the magnetic resonance system in response to a magnetic resonance control signal received by the resonator device. The electromagnetic field sensor device is configured to sense the electromagnetic field generated by the resonator device. The switch device includes a first input port, a second input port, an output port, and a control port. The first input port of the switch device is coupled to the resonator device. The second input port of the switch device is coupled to the electromagnetic field sensor device. The control port of the switch device is configured to receive a digital control signal. The output port of the switch device is configured to be coupled to a receiver circuit of the magnetic resonance system. The switch device is configured to selectively couple the first input port of the switch device or the second input port of the switch device to the output port of the switch device depending on the state of the digital control signal.

[0162] Implementations of the seventh example may include one or more of the following features: The resonator device includes a low noise amplifier (LNA) device. The LNA device includes an LNA input port and an LNA output port. The LNA input port is coupled to an output port of the switch device, and the LNA output port is configured to be coupled to the receiver circuit. The resonator circuit includes a limiter device coupled between the output port of the switch device and the LNA input port. The limiter device includes an input port and an output port. The resonator circuit includes a bandpass filter coupled between the output port of the switch device and the input port of the limiter device.

[0163] In a seventh embodiment, the resonator circuit is configured to operate in a cryogenic environment of a magnetic resonance system. The switch device is configured to switch between a first state and a second state in response to a change in state of a digital control signal. The first state includes an output port of the switch device being coupled to a first input port of the switch device and disconnected from a second input port of the switch device. The second state includes an output port of the switch device being coupled to the second input port of the switch device and disconnected from the first input of the switch device.

[0164] In a seventh embodiment, a resonator circuit is configured to operate in a cryogenic environment of a magnetic resonance system. The resonator device includes an input port and an output port and is configured to operate in a transmission mode. A first input port of a switch device is coupled to the output port of the resonator device. The switch device is a first switch device. The resonator circuit includes a second switch device. The second switch device includes an input port and an output port. The output port of the second switch device is coupled to the input port of the resonator device, and the input port of the second switch device is configured to receive a magnetic resonance control signal.

[0165] In a seventh embodiment, a resonator circuit is configured to operate in a cryogenic environment of a magnetic resonance system. The digital control signal on the first switch device is a first digital control signal. The second switch device includes a control port configured to receive the second digital control signal and is configured to switch between a first state and a second state in response to a change in state of the second digital control signal. The first state includes an input port of the second switch device being coupled to an output port of the second switch device. The second state includes an input port of the second switch device being disconnected from the output port of the second switch device. The switching time of the second switch device is 30 nanoseconds or less.

[0166] In a seventh embodiment, a resonator circuit is configured to operate in a cryogenic environment of a magnetic resonance system. The resonator device includes an input / output port and is configured to operate in a reflection mode. A first input port of a switch device is coupled to the input / output port of the resonator device. The switch device is a first switch device. The resonator circuit includes a circulator device and a second switch device. The circulator device includes an input port, an input / output port coupled to the input / output port of the resonator device, and an output port coupled to the first input port of the first switch device. The second switch device includes an input port configured to receive a magnetic resonance control signal and an output port coupled to the input port of the circulator device. The electromagnetic field sensor device includes a coil device for sensing a magnetic field. The electromagnetic field sensor device includes a resistor device for sensing an electric field.

[0167] In an eighth embodiment, there is provided a resonator circuit in a magnetic resonance system, the resonator circuit including a resonator device, an electromagnetic field sensor, and a switch device. A method of operating a resonator circuit includes receiving a first resonator control signal at the resonator device while the switch device is in a first state, generating a first electromagnetic field in a sample volume of a magnetic resonance system in response to the first magnetic resonance control signal by operating the resonator, obtaining a first magnetic resonance detection signal by operating the resonator device based on an interaction of the resonator with a sample in the sample volume, communicating the first magnetic resonance detection signal to a receiver circuit of the magnetic resonance system via the switch device, switching the switch device from the first state to a second state in response to the digital control signal received at the switch device, receiving a second magnetic resonance control signal at the resonator device while the switch device is in the second state, generating a second electromagnetic field in the sample volume of the magnetic resonance system in response to the second magnetic resonance control signal by operating the resonator device, operating an electromagnetic field sensor to generate a sensor output signal based on an interaction of the second electromagnetic field with the electromagnetic field sensor, and communicating the sensor output signal to the receiver circuit via the switch device.

[0168] Implementations of the eighth example may include one or more of the following features: the resonator circuit includes a low noise amplifier (LNA) device, and the method includes communicating the first magnetic resonance detection signal from the switch device through the LNA device before communicating the first magnetic resonance detection signal through the switch device to the receiver circuit, and communicating the sensor output signal from the switch device through the LNA device before communicating the sensor output signal through the switch device to the receiver circuit.

[0169] Implementations of the eighth example may include one or more of the following features: the resonator circuit includes a limiter device, communicating the first magnetic response detection signal from the switch device to the LNA device includes communicating the first magnetic response detection signal from the switch device to the LNA device via the limiter device, and communicating the sensor output signal from the switch device to the LNA device includes communicating the sensor output signal from the switch device to the LNA device via the limiter device.

[0170] Implementations of the eighth example may include one or more of the following features: the resonator circuit includes a bandpass filter device, and the method includes communicating the first magnetic resonance detection signal from the switch device to the limiter device through the bandpass filter device and communicating the sensor output signal from the switch device to the limiter device through the bandpass filter device.

[0171] Implementations of the eighth example embodiment may include one or more of the following features: a resonator device including an input port and an output port and configured to operate in a transmission mode, wherein communicating the first magnetic resonance detection signal through the switch device to a receiver circuit of the magnetic resonance system includes communicating the first magnetic resonance detection signal from the output port of the resonator device through the switch device to the receiver circuit of the magnetic resonance system.

[0172] Implementations of the eighth example may include one or more of the following features: the switch device is a first switch device; the resonator circuit includes a second switch device; and the second switch device has a switching time of 30 nanoseconds or less. The method includes receiving a first or second magnetic resonance control signal at the second switch device and communicating the first or second magnetic resonance control signal from the second switch device to an input port of the resonator device.

[0173] Implementations of the eighth example may include one or more of the following features: A resonator device includes an input / output port and is configured to operate in a reflection mode. Communicating the first magnetic resonance detection signal through the switch device to a receiver circuit of the magnetic resonance system includes communicating the first magnetic resonance detection signal from the input / output port of the resonator device through the switch device to the receiver circuit of the magnetic resonance system.

[0174] Implementations of the eighth example may include one or more of the following features: the switch device is a first switch device; the resonator circuit includes a circulator device and a second switch device; the circulator device includes an input port, an input / output port, and an output port; and the second switch device includes an input port and an output port. The method includes receiving a first or second magnetic resonance control signal at an input port of the second switch device while the second switch device is in a first state, communicating the first or second magnetic resonance control signal from the input port of the second switch device to an output port of the second switch device, communicating the first or second magnetic resonance control signal from the input port of the circulator device through the input / output port of the circulator device to an input / output port of the resonator device, receiving a first magnetic resonance detection signal from the input / output port of the resonator device at the input / output port of the circulator device, and communicating the first magnetic resonance detection signal from the input / output port of the circulator device through the output port of the circulator device to the first switch device.

[0175] While many details are set forth herein, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of features specific to particular examples. Certain features that are described herein or illustrated in the drawings in the context of separate implementations may also be combined. Conversely, various features that are described and illustrated in the context of a single implementation may also be implemented in multiple embodiments separately or in any suitable subcombination.

[0176] Similarly, although the figures show operations in a particular order, this should not be understood as requiring that such operations be performed in the particular order or sequential order shown, or that all of the operations shown be performed, to achieve desirable results. In certain situations, multitasking and parallel processing may be advantageous. Also, the separation of various system components in the above-described implementations should not be understood as requiring such separation in all implementations, and it should be understood that the program components and systems described may generally be integrated into a single product or packaged as multiple products.

[0177] Although certain embodiments have been described above, it will be understood that various modifications may be made and, therefore, other embodiments are within the scope of the following claims.

Claims

1. 1. An amplifier circuit for a magnetic resonance system, comprising: a first switch device including an input port, a first output port, a second output port, and a control port, the input port of the first switch device configured to receive a magnetic resonance control signal, the control port of the first switch device configured to receive a first digital control signal, and the first switch device configured to selectively couple the input port of the first switch device to the first output port or the second output port of the first switch device based on a state of the first digital control signal; a high power amplifier (HPA) device including an HPA input port and an HPA output port, the HPA input port coupled to the first output port of the first switch device; a second switch device including an input port, an output port, and a control port, the control port of the second switch device configured to receive a second digital control signal, and the second switch device configured to selectively couple the input port of the second switch device to the output port of the second switch device based on a state of the second digital control signal; an amplifier circuit comprising: a power combiner device including a first input port, a second input port, and an output port, wherein the first input port of the power combiner device is coupled to the output port of the second switch device, the second input port of the power combiner device is coupled to the second output port of the first switch device along a path that bypasses the HPA device, and the output port of the power combiner device is configured to be coupled to a resonator circuit of the magnetic resonance system.

2. 10. The amplifier circuit of claim 1, wherein the amplifier circuit is configured to operate at room temperature and the resonator circuit is configured to operate at cryogenic temperatures.

3. 10. The amplifier circuit of claim 1, wherein the amplifier circuit is configured to operate at room temperature and at least a portion of the resonator circuit is configured to operate at room temperature.

4. The amplifier circuit of claim 1 , further comprising a bandpass filter device coupled between the HPA output port and the first input port of the power combiner device.

5. the first switch device is configured to switch between a first state and a second state in response to a change in state of the first digital control signal; the first state includes the input port of the first switch device being coupled to the first output port of the first switch device and being disconnected from the second output port of the first switch device; the second state includes the input port of the first switch device being coupled to the second output port of the first switch device and being disconnected from the first output port of the first switch device; 5. The amplifier circuit of claim 1, wherein the first switch device has a switching time of 1 microsecond (μsec) or less.

6. the second switch device is configured to switch between a first state and a second state in response to a change in the state of the second digital control signal; the first state includes the input port of the second switch device being coupled to the output port of the second switch device; the second state includes the input port of the second switch device being disconnected from the output port of the second switch device; 5. The amplifier circuit of claim 1, wherein the second switch device has a switching time of 1 μsec or less.

7. 1. A method of operating an amplifier circuit in a magnetic resonance system, the amplifier circuit including a first switch device, a high power amplifier (HPA) device, a second switch device, and a power combiner device, the method comprising: While the first switch device is in a first state, receiving a first magnetic resonance control signal at the first switch device; communicating the first magnetic resonance control signal from the first switch device to the HPA device; amplifying the first magnetic resonance control signal by operation of the HPA device; receiving an amplified magnetic resonance signal from the HPA device at the second switch device; communicating the amplified magnetic resonance signal through the second switch device to the power combiner device; providing a first output of the power combiner device to a resonator circuit of the magnetic resonance system; switching the first switch device from the first state to a second state in response to a digital control signal received by the first switch device; While the first switch device is in the second state, receiving a second magnetic resonance control signal at the first switch device; communicating the second magnetic resonance control signal from the first switch device to the power combiner device, wherein communicating the second magnetic resonance control signal from the first switch device to the power combiner device bypasses the HPA; and and providing a second output of the power combiner device to the resonator circuit of the magnetic resonance system.

8. The method of claim 7 , wherein the amplifier circuit operates at room temperature and the resonator circuit operates at cryogenic temperatures.

9. The method of claim 7 , wherein the amplifier circuit operates at room temperature and at least a portion of the resonator circuit operates at room temperature.

10. 8. The method of claim 7, wherein communicating the amplified magnetic resonance signal to the power combiner device via the second switch device includes communicating the amplified magnetic resonance signal to the power combiner device via a bandpass filter device.

11. 8. The method of claim 7, wherein the first switch device switches from the first state to the second state in a switching time of less than 1 microsecond.

12. 8. The method of claim 7, comprising arbitrarily switching the switch device between the second state and the first state such that the magnetic resonance system can be switched between a continuous wave mode of operation and a pulsed mode of operation.

13. 1. A resonator circuit configured to operate in a cryogenic environment of a magnetic resonance system, comprising: a resonator device including an input port, an output port, and a resonator coupled between the input port and the output port, the input port of the resonator device configured to receive a magnetic resonance control signal, and the resonator device configured to generate an electromagnetic field in a sample volume of the magnetic resonance system in response to the magnetic resonance control signal; a low noise amplifier (LNA) device including an LNA input port and an LNA output port, the LNA input port being coupled to the output port of the resonator device, and the LNA output port being configured to be coupled to receiver circuitry of the magnetic resonance system;

14. The resonator circuit of claim 13 including a switch device coupled between the output port of the resonator device and the LNA input port.

15. 15. The resonator circuit of claim 14, wherein the switch device includes an input port, a first output port, and a second output port, and the resonator circuit includes a limiter device coupled between the first output port of the switch device and the LNA input port.

16. 16. The resonator circuit of claim 15, wherein the limiter device includes an input port and an output port, and the resonator circuit includes a bandpass filter device coupled between the first output port of the switch device and the input port of the limiter device.

17. the switch device includes a control port configured to receive a digital control signal and configured to switch between a first state and a second state in response to a change in state of the digital control signal; the first state includes the input port of the switch device being coupled to the first output of the switch device and disconnected from the second output port of the switch device; 15. The resonator circuit of claim 14, wherein the second state comprises the input port of the switch device being coupled to the second output port of the device and disconnected from the first output port of the switch device.

18. 14. The resonator circuit of claim 13, comprising a switch device, the switch device including an input port and an output port, the output port of the switch device coupled to the input port of the resonator device, and the input port of the switch device configured to receive the magnetic resonance control signal.

19. the switch device includes a control port configured to receive a digital control signal and configured to switch between a first state and a second state in response to a change in state of the digital control signal; the first state includes the input port of the switch device being coupled to the output port of the switch device; the second state includes the input port of the switch device being disconnected from the output port of the switch device; 20. The resonator circuit of claim 18, wherein the switching time of the switch device is 30 nanoseconds (ns) or less.

20. 1. A method of operating a resonator circuit in a magnetic resonance system, the resonator circuit including a resonator device and a low noise amplifier (LNA) device, the resonator device including an input port, an output port, and a resonator coupled between the input port and the output port, the method comprising: receiving a magnetic resonance control signal at the input port of the resonator device; generating an electromagnetic field in a sample volume of the magnetic resonance system in response to the magnetic resonance control signal by operation of the resonator device; operating the resonator device to obtain a magnetic resonance detection signal based on an interaction between the resonator device and a sample in the sample volume; providing the magnetic resonance detection signal from the output of the resonator device to the LNA device; amplifying the magnetic resonance detection signal by operating the LNA device; and providing the amplified magnetic resonance detection signal to receiver circuitry of the magnetic resonance system.

21. the resonator circuit includes a switch device, and the method comprises: While the switch device is in a first state, receiving the magnetic resonance detection signal from the output port of the resonator device at the switch device; and communicating the magnetic resonance detection signal from the switch device to the LNA device.

22. 22. The method of claim 21, comprising communicating the magnetic resonance detection signal from the switch device to a limiter device coupled between the switch device and the LNA device before amplifying the magnetic resonance detection signal.

23. switching the switch device from the first state to a second state in response to a digital control signal received by the switch device; While the switch device is in the second state, receiving the magnetic resonance detection signal from the output of the resonator device at the switch device; and communicating the magnetic resonance detection signal from the switch device along a path that bypasses the LNA device.

24. 24. The method of claim 23, further comprising switching the switch device between the first state and the second state such that a magnetic resonance system is switched between a measurement mode of operation and a pulse observation mode of operation.

25. the resonator circuit includes a switch device, the switch device having a switching time of 30 nanoseconds (ns) or less, and the method further comprising: prior to receiving the magnetic resonance control signal at the input port of the resonator device, while the switch device is in a first state; receiving the magnetic resonance control signal at the switch device; and communicating the magnetic resonance control signal from the switch device to the input port of the resonator device.

26. 1. A resonator circuit configured to operate in a cryogenic environment of a magnetic resonance system, comprising: a resonator device including a resonator configured to generate an electromagnetic field in a sample volume of the magnetic resonance system in response to a magnetic resonance control signal received by the resonator device; a switch device including an input port, a first output port, a second output port, and a control port, wherein the input port of the switch device is coupled to the resonator device, the control port of the switch device is configured to receive a digital control signal, the switch device is configured to selectively couple the input port of the switch device to the first output port or the second output port of the switch device based on a state of the digital control signal, and the second output port of the switch device is configured to be coupled to receiver circuitry of the magnetic resonance system along a path that bypasses a low noise amplifier (LNA) device; A resonator circuit, wherein the LNA device includes an LNA input port and an LNA output port, the LNA input port being coupled to the first output port of the switch device, and the LNA output port being configured to be coupled to the receiver circuit of the magnetic resonance system.

27. 27. The resonator circuit of claim 26, comprising a limiter device coupled between the first output port of the switch device and the LNA input port.

28. 28. The resonator circuit of claim 27, wherein the limiter device includes an input port and an output port, and the resonator circuit includes a bandpass filter device coupled between the first output port of the switch device and the input port of the limiter device.

29. the switch device is configured to switch between a first state and a second state in response to the change in state of the digital control signal; the first state includes the input port of the switch device being coupled to the first output port of the switch device and disconnected from the second output port of the switch device; 27. The resonator circuit of claim 26, wherein the second state comprises the input port of the switch device being coupled to the second output port of the switch device and disconnected from the first output port of the switch device.

30. 27. The resonator circuit of claim 26, wherein the resonator device includes an input port and an output port and is configured to operate in a transmission mode, the first input port of the switch device being coupled to the output port of the resonator device.

31. 31. The resonator circuit of claim 30, wherein the switch device is a first switch device, and the resonator circuit includes a second switch device, the second switch device including an input port and an output port, the output port of the second switch device coupled to the input port of the resonator device, and the input port of the second switch device configured to receive the magnetic resonance control signal.

32. the digital control signal received by the first switch device is a first digital control signal; the second switch device includes a control port configured to receive a second digital control signal and configured to switch between a first state and a second state in response to a change in state of the second digital control signal; the first state includes the input port of the second switch device being coupled to the output port of the second switch device; the second state includes the input port of the second switch device being disconnected from the output port of the second switch device; 31. The resonator circuit of claim 30, wherein the second switch device has a switching time of 30 nanoseconds (ns) or less.

33. 27. The resonator circuit of claim 26, wherein the resonator device includes an input / output port and is configured to operate in a reflective mode, the input port of the switch device being coupled to the input / output port of the resonator device.

34. 34. The resonator circuit of claim 33, wherein the switch device is a first switch device, the resonator circuit includes a circulator device and a second switch device, the circulator device includes an input port, an input / output port coupled to the input / output port of the resonator device, and an output port coupled to the first input port of the first switch device, and the second switch device includes an input port configured to receive the magnetic resonance control signal and an output port coupled to the input port of the circulator device.

35. 35. The resonator circuit of claim 34, wherein the circulator device is a directional coupler device.

36. 35. The resonator circuit of claim 34, wherein the circulator device is a quarter-wave transformer.

37. 1. A method of operating a resonator circuit in a magnetic resonance system, the resonator circuit including a resonator device, a switch device, and a low noise amplifier (LNA) device, the method comprising: While the switch device is in a first state, receiving a first magnetic resonance control signal at the resonator device; generating a first electromagnetic field in a sample volume of the magnetic resonance system in response to the first magnetic resonance control signal by operation of the resonator; operating the resonator device to obtain a first magnetic resonance detection signal based on an interaction between the resonator and a sample in the sample volume; communicating the magnetic resonance detection signal to the LNA device through the switch device; amplifying the magnetic resonance detection signal by operating the LNA device; transmitting the amplified output to receiver circuitry of the magnetic resonance system; switching the switch device from the first state to a second state in response to a digital control signal received at the switch device; While the switch device is in the second state, receiving a second magnetic resonance control signal at the resonator device; generating a second electromagnetic field in the sample volume of the magnetic resonance system in response to the second magnetic resonance control signal by operation of the resonator device; operating the resonator device to obtain a second magnetic resonance detection signal based on an interaction between the resonator and the sample; and communicating the second magnetic resonance detection signal to the receiver circuitry via the switch device along a path that bypasses the LNA device.

38. the resonator circuit includes a limiter device, and the first magnetic resonance detection signal is transmitted to the LNA device via the switch device; receiving the first magnetic resonance detection signal at the limiter device from the switch device; and communicating the first magnetic resonance detection signal from the limiter device to the LNA device.

39. the resonator circuit includes a bandpass filter device, and the first magnetic resonance detection signal is transmitted to the LNA device via the switch device; receiving the first magnetic resonance detection signal at the bandpass filter device from the switch device; and communicating the first magnetic resonance detection signal from the bandpass filter device to the limiter device.

40. the resonator device includes an input port and an output port, and is configured to operate in a transmission mode, and communicates the first magnetic resonance detection signal to the LNA device through the switch device; 38. The method of claim 37, comprising communicating the first magnetic resonance detection signal from the output port of the resonator device through the switch device to the LNA device.

41. communicating the second magnetic resonance detection signal to the receiver circuitry via the switch device along a path that bypasses the LNA device; 41. The method of claim 40, comprising communicating the second magnetic resonance detection signal from the output port of the resonator device to the receiver circuit along the path that bypasses the LNA device.

42. the switch device is a first switch device, the resonator circuit includes a second switch device, the second switch device has a switching time of 30 nanoseconds (ns) or less, and the method further comprises: receiving the first or second magnetic resonance control signal at the second switch device; and communicating the first or second magnetic resonance control signal from the second switch device to the input port of the resonator device.

43. 38. The method of claim 37, comprising switching the switch device between the first state and the second state such that the magnetic resonance system is switched between a measurement mode of operation and an observation mode of operation.

44. the resonator device includes an input / output port and is configured to operate in a reflection mode, and communicates the magnetic resonance detection signal to the LNA device through the switch device; 38. The method of claim 37, comprising communicating the first magnetic resonance detection signal from the input / output port of the resonator device through the switch device to the LNA device.

45. communicating the second magnetic resonance detection signal through the switch device to the receiver circuit along a path that bypasses the LNA device; 45. The method of claim 44, comprising communicating the second magnetic resonance detection signal from the input / output port of the resonator circuit to the receiver circuit along the path that bypasses the LNA device.

46. the switch device is a first switch device, the resonator circuit includes a circulator device and a second switch device, the circulator device includes an input port, an input / output port, and an output port, the second switch device includes an input port and an output port, and the method comprises: While the second switch device is in a first state, receiving the first or second magnetic resonance control signal at the input port of the second switch device; communicating the first or second magnetic resonance control signal from the input port of the second switch device to the output port of the second switch device; communicating the first or second magnetic resonance control signal from the input port of the circulator device through the input / output port of the circulator device to the input / output port of the resonator device; receiving the first or second magnetic resonance detection signal from the input / output port of the resonator device at the input / output port of the circulator device; and communicating the first or second magnetic resonance detection signal from the input / output port of the circulator device through the output port of the circulator device to the first switch device.

47. 47. The method of claim 46, wherein the circulator device is a directional coupler device.

48. 47. The method of claim 46, wherein the circulator device is a quarter-wave transformer.

49. 1. A resonator circuit configured to operate in a cryogenic environment of a magnetic resonance system, comprising: a resonator device including a resonator configured to generate an electromagnetic field in a sample volume of the magnetic resonance system in response to a magnetic resonance control signal received by the resonator device; an electromagnetic field sensor device configured to sense the electromagnetic field generated by the resonator device; 1. A switch device including a first input port, a second input port, an output port, and a control port, wherein the first input port of the switch device is coupled to the resonator device, the second input port of the switch device is coupled to the electromagnetic wave sensor device, the control port of the switch device is configured to receive a digital control signal, and the output port of the switch device is configured to be coupled to a receiver circuit of the magnetic resonance system, and the switch device is configured to selectively couple the first input port of the switch device or the second input port of the switch device to the output port of the switch device depending on a state of the digital control signal.

50. 50. The resonator circuit of claim 49, comprising a low noise amplifier (LNA) device including an LNA input port and an LNA output port, the LNA input port configured to be coupled to the output port of the switch device and the LNA output port configured to be coupled to the receiver circuit.

51. 51. The resonator circuit of claim 50, comprising a limiter device coupled between the output port of the switch device and the LNA input port.

52. 52. The resonator circuit of claim 51 , wherein the limiter device includes an input port and an output port, and the resonator circuit includes a bandpass filter coupled between the output port of the switch device and the input port of the limiter device.

53. the switch device is configured to switch between a first state and a second state in response to the change in state of the digital control signal; the first state includes the output port of the switch device being coupled to the first input port of the switch device and disconnected from the second input port of the switch device; 50. The resonator circuit of claim 49, wherein the second state comprises the output port of the switch device being coupled to the second input port of the switch device and disconnected from the first input port of the switch device.

54. 50. The resonator circuit of claim 49, wherein the resonator device includes an input port and an output port and is configured to operate in a transmission mode, the first input port of the switch device being coupled to the output port of the resonator device.

55. 50. The resonator circuit of claim 49, wherein the switch device is a first switch device, and the resonator circuit includes a second switch device, the second switch device including an input port and an output port, the output port of the second switch device coupled to the input port of the resonator device, and the input port of the second switch device configured to receive the magnetic resonance control signal.

56. the digital control signal received by the first switch device is a first digital control signal; the second switch device includes a control port configured to receive a second digital control signal and configured to switch between a first state and a second state in response to a change in state of the second digital control signal; the first state includes the input port of a second switch device being coupled to the output port of the second switch device; the second state includes the input port of the second switch device being disconnected from the output port of the second switch device; 56. The resonator circuit of claim 55, wherein the second switch device has a switching time of 30 nanoseconds (ns) or less.

57. 50. The resonator circuit of claim 49, wherein the resonator device includes an input / output port and is configured to operate in a reflective mode, the first input port of the switch device being coupled to the input / output port of the resonator device.

58. 58. The resonator circuit of claim 57, wherein the switch device is a first switch device, the resonator circuit includes a circulator device and a second switch device, the circulator device includes an input port, an input / output port coupled to the input / output port of the resonator device, and an output port coupled to the first input port of the first switch device, and the second switch device includes an input port configured to receive the magnetic resonance control signal and an output port coupled to the input port of the circulator device.

59. 57. The resonator circuit of claim 56, wherein the circulator device is a directional coupler device.

60. 60. The resonator circuit of claim 59, wherein the circulator device is a quarter-wave transformer.

61. 50. The resonator circuit of claim 49, wherein the electromagnetic field sensor device comprises a coil device for sensing a magnetic field.

62. 50. The resonator circuit of claim 49, wherein the electromagnetic field sensor device comprises a resistor device for sensing an electric field.

63. 1. A method of operating a resonator circuit in a magnetic resonance system, the resonator circuit including a resonator device, an electromagnetic field sensor, and a switch device, the method comprising: While the switch device is in a first state, receiving a first magnetic resonance control signal at the resonator device; generating a first electromagnetic field in a sample volume of the magnetic resonance system in response to the first magnetic resonance control signal by operation of the resonator; operating the sensor device to obtain a first magnetic resonance detection signal based on an interaction between the resonator and a sample in the sample volume; communicating the first magnetic resonance detection signal through the switch device to a receiver circuit of the magnetic resonance system; switching the switch device from the first state to a second state in response to a digital control signal received at the switch device; While the switch device is in the second state, receiving a second magnetic resonance control signal at the resonator device; generating a second electromagnetic field in the sample volume of the magnetic resonance system in response to the second magnetic resonance control signal by operation of the resonator device; operating the electromagnetic field sensor to generate a sensor output signal based on an interaction of the second electromagnetic field with the electromagnetic field sensor; and communicating the sensor output signal through the switch device to the receiver circuit.

64. the resonator circuit includes a low noise amplifier (LNA) device, and the method further comprises: communicating the first magnetic resonance detection signal from the switch device through the LNA device before communicating the first magnetic resonance detection signal through the switch device to the receiver circuit; 64. The method of claim 63, comprising communicating the sensor output signal from the switch device through the LNA device before communicating the sensor output signal through the switch device to the receiver circuit.

65. the resonator circuit includes a limiter device; communicating the first magnetic resonance detection signal from the switch device to the LNA device includes communicating the first magnetic resonance detection signal from the switch device to the LNA device through the limiter device; 65. The method of claim 64, wherein communicating the sensor output signal from the switch device to the LNA device comprises communicating the sensor output signal from the switch device to the LNA device through the limiter device.

66. the resonator circuit includes a bandpass filter device, and the method further comprises: communicating the first magnetic resonance detection signal from the switch device to the limiter device through the bandpass filter device; and communicating the sensor output signal from the switch device to the limiter device through the bandpass filter device.

67. the resonator device including an input port and an output port and configured to operate in a transmission mode, communicating the first magnetic resonance detection signal through the switch device to the receiver circuit of the magnetic resonance system; 64. The method of claim 63, comprising communicating the first magnetic resonance detection signal from the output port of the resonator device through the switch device to the receiver circuitry of the magnetic resonance system.

68. the switch device is a first switch device, the resonator circuit includes a second switch device, the second switch device has a switching time of 30 nanoseconds (ns) or less, and the method further comprises: receiving the first or second magnetic resonance control signal at the second switch device; and communicating the first or second magnetic resonance control signal from the second switch device to the input port of the resonator device.

69. the resonator device includes an input / output port and is configured to operate in a reflection mode, and communicates the first magnetic resonance detection signal to the receiver circuit of the resonator system through the switch device; 64. The method of claim 63, comprising communicating the first magnetic resonance detection signal from the input / output port of the resonator device through the switch device to the receiver circuitry of the magnetic resonance system.

70. 64. The method of claim 63, comprising switching the switch device between the first state and the second state such that the magnetic resonance system can be switched between a measurement mode of operation and a pulse observation mode of operation.

71. the switch device is a first switch device, the resonator circuit includes a circulator device and a second switch device, the circulator device includes an input port, an input / output port, and an output port, the second switch device includes an input port and an output port, and the method comprises: While the second switch is in the first state, receiving the first or second magnetic resonance control signal at the input port of the second switch device; communicating the first or second magnetic resonance control signal from the input port of the second switch to the output port of the second switch device; communicating the first or second magnetic resonance control signal from an input port of the circulator device to an input / output port of the resonator device via an input / output port of the circulator device; receiving the first magnetic resonance detection signal at the input / output port of the circulator device from the input / output port of the resonator device; and communicating the first magnetic resonance detection signal from the input / output port of the circulator device to the first switch device via an output port of the circulator device.

72. 72. The method of claim 71, wherein the circulator device is a directional coupler device.

73. 72. The method of claim 71, wherein the circulator device is a quarter-wave transformer.

74. 1. A magnetic resonance system comprising: a primary magnet system; a resonator unit including a resonator device; means for switching said magnetic resonance system between a continuous wave mode of operation and a pulsed mode of operation.

75. 75. The magnetic resonance system of claim 74, wherein the means for switching includes a control unit that controls the state of each of one or more switches in the magnetic resonance system.

76. operating the magnetic resonance system in a continuous wave mode of operation; operating the magnetic resonance system in a pulsed mode of operation; switching the magnetic resonance system between the pulsed mode of operation and the continuous wave mode of operation.

77. 77. The magnetic resonance method of claim 76, wherein the magnetic resonance system includes a plurality of switches, and switching the magnetic resonance system between the pulsed mode of operation and the continuous wave mode of operation includes executing control logic to manipulate the state of each of the plurality of switches.

78. 1. A magnetic resonance system comprising: a primary magnet system; a resonator unit including a resonator device; means for switching said magnetic resonance system between a measurement mode of operation and a pulse observation mode of operation.

79. 79. The magnetic resonance system of claim 78, wherein the means for switching includes a control unit that controls the state of each of one or more switches in the magnetic resonance system.

80. operating the magnetic resonance system in a measurement mode of operation; operating the magnetic resonance system in a pulsed observation mode of operation; switching the magnetic resonance system between the measurement mode of operation and the pulse observation mode of operation.

81. 81. The magnetic resonance method of claim 80, wherein the magnetic resonance system includes a plurality of switches, and switching the magnetic resonance system between a measurement mode of operation and a pulse observation mode of operation includes executing control logic to manipulate the state of each of the plurality of switches.

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