Radio frequency (RF) power module with high frequency switching electronic power regulator in combination with millimeter wave to terahertz vacuum electronics

Abstract

A power module includes a high frequency switching electronic power regulator including a stacked rectifier / filter, the stacked rectifier / filter generating a stacked DC output voltage; and vacuum electronics coupled to the high frequency switching electronic power regulator, the vacuum electronics including components, each component receiving a respective one of the stacked DC output voltages.

Description

Technical Field

[0001] This invention relates generally to radio frequency (RF) power modules, and more specifically to an RF power module having a high-frequency switching electronic power regulator in conjunction with millimeter-wave to terahertz vacuum electronic devices. Background Technology

[0002] Radio frequency (RF) power modules (such as RF power amplifiers or oscillators) are used as RF generation or amplification stages in RF networks for a variety of applications, including imaging, radar, and communications. Millimeter-wave, Asia-Pacific Hertz, and terahertz power modules are needed to achieve high resolution in imaging and radar systems or high data rates in communication systems. Summary of the Invention

[0003] Radio frequency (RF) power modules (such as RF power amplifiers or oscillators) serve as RF generation or amplification stages in RF networks for a wide range of applications, including imaging, radar, communications, and others. Millimeter-wave, terahertz, and ultra-high-frequency (UHQF) power modules are required to achieve high resolution in imaging and radar systems and high data rates in communication systems. High-frequency switching electronic power conditioners offer a compact approach to achieving relatively high output voltages. The combination of high-frequency switching electronic power conditioners with millimeter-wave and up-terahertz vacuum electronics enables the implementation of compact and efficient RF power modules.

[0004] Traditionally, achieving both efficiency and power density simultaneously in electronic power regulators has been challenging (especially at relatively high voltages (up to 30 kV) and in electronic power regulators operating with high efficiency (over 85%). Furthermore, as systems operate at lower power levels (such as those achievable in millimeter-wave to terahertz vacuum electronics), the achievable power density typically decreases.

[0005] To achieve high efficiency and compact size in electronic power conditioners, high-frequency switching power supply topologies can be used. Increasing the frequency switching to levels greater than 1 MHz improves the power density of lower voltage (<1 kV) power converters. This significant increase in frequency allows for a reduction in the in-value of passive components in the converter, enabling a substantial reduction in size. For high-voltage electronic power conditioners, this is particularly beneficial for magnetic components and output capacitors. Furthermore, the reduction in output capacitance with increasing output voltage reduces the available stored energy in the electronic power conditioner and the resulting power module, allowing for safer operation in the event of system failure. The use of resonant inverter-rectifier converter topologies reduces switching losses, achieving both compact and efficient energy conversion.

[0006] To achieve high efficiency in vacuum electronic devices, multi-stage depressed collectors can be used. The electromagnetic design of vacuum electronic devices focuses on utilizing the various potential interaction mechanisms between the electron beam and the co-propagating electromagnetic wave. After the interaction between the electron beam and the electromagnetic wave is complete, the spent electrons in the electron beam typically exhibit energy diffusion, meaning that these spent electrons travel at various speeds. Depressed collectors enable matching the electron potential of these spent electrons, thus "recovering" their kinetic energy back to the power source, rather than converting it into heat. As a result, only the mismatch between the actual electron energy and the electron potential of the individual collector electrodes is converted into heat. Notably, depressed collectors have been shown to convert electron beam energy back into current with efficiencies up to 99%.

[0007] The number of step-down current collector stages plays a role in the current collector's energy recovery efficiency. Due to the stacked output design of the high-frequency resonant converter technology, the high-frequency switching electronic power conditioner allows for easy access to multiple current collector voltages at various potentials, thereby optimizing the overall system efficiency.

[0008] In some embodiments, the present invention provides a power module including a high-frequency switching electronic power regulator including a stacked rectifier / filter that generates a stacked DC output voltage; and a vacuum electronics device coupled to the high-frequency switching electronic power regulator, the vacuum electronics device including components, each component receiving a corresponding DC output voltage in the stacked DC output voltage.

[0009] High-frequency switching electronic power regulators can have switching frequencies higher than 1 MHz. Vacuum electronic devices can operate at frequencies between 28 GHz and 280 GHz. Vacuum electronic devices can operate at frequencies between 280 GHz and 2.8 THz. High-frequency switching electronic power regulators can employ a resonant topology. Components may include a set of buck collector stages, and the stacked DC output voltage may include a set of DC output voltages for the set of buck collector stages. Components may include a cathode and a cathode heater, and the stacked DC output voltage may include a cathode voltage and a cathode heater voltage. The cathode heater voltage may be referenced to the cathode voltage (floating on the cathode voltage).

[0010] A high-frequency switching electronic power conditioner may include a high-frequency inverter; a resonant tank; a transformer coupled to the resonant tank and the stacked resonant rectifier / filter; and a controller configured to control the characteristics of the high-frequency inverter to control the DC output voltage according to specified tolerances. The controller can control the timing of the switching elements of the high-frequency inverter. The transformer may include a primary winding and a set of secondary windings, each secondary winding coupled to a corresponding one of the stacked rectifier / filters. Components may include a cathode, a cathode heater, and a set of step-down current collector stages.

[0011] A high-frequency switching electronic power conditioner may have a set of two or more power converter stages, each power converter stage including a high-frequency inverter; a resonant tank; and a transformer coupled to a corresponding one of the resonant tank and a stacked rectifier / filter. Each power converter stage may have a controller configured to control the characteristics of the high-frequency inverter to control the corresponding DC output voltage of the power converter stage. At least one controller of at least one power converter stage may control the timing of the switching elements of the high-frequency inverter of the power converter stage. The controller may be configured to control the stability of the corresponding DC output voltage to a specified tolerance. A particular power converter stage may be configured to generate at least two DC output voltages, and the controller may be configured to control the stability of at least two DC output voltages to a specified tolerance. The transformer may include a primary winding and a secondary winding, the secondary winding being coupled to a corresponding one of the stacked rectifier / filter. A particular power converter stage may have a controller configured to control the characteristics of the high-frequency inverter to control the corresponding DC output voltage of the particular power converter stage. The controller may be configured to control the stability of the corresponding DC output voltage to a specified tolerance. Attached Figure Description

[0012] Figure 1 This is a diagram illustrating a power module according to some embodiments of the present invention, the power module including a high-frequency switching electronic power regulator combined with millimeter-wave to terahertz vacuum electronics.

[0013] Figure 2 This is a diagram illustrating a high-frequency switching electronic power regulator that provides a single direct current (DC) output voltage according to some embodiments of the present invention.

[0014] Figure 3A This is a diagram illustrating a high-frequency switching electronic power regulator with parallel rectifiers / filters to generate multiple DC output voltages according to some embodiments of the present invention.

[0015] Figure 3B This illustrates some embodiments according to the present invention. Figure 3A A diagram of a high-frequency switching electronic power regulator.

[0016] Figure 4A This is a diagram illustrating a high-frequency switching electronic power regulator with parallel power converters to generate multiple DC output voltages according to some embodiments of the present invention.

[0017] Figure 4B This illustrates some embodiments according to the present invention. Figure 4A A diagram of a high-frequency switching electronic power regulator.

[0018] Figure 5 This is a diagram illustrating a stacked rectifier / filter 408 according to some embodiments of the present invention, which stacks corresponding DC output voltages Vdc to power different components of the vacuum electronics 104. Detailed Implementation

[0019] The following description is provided to enable those skilled in the art to make and use various embodiments of the invention. Modifications are possible. The general principles defined herein may be applied to the disclosed embodiments and other embodiments without departing from the spirit and scope of the invention. Therefore, the claims are not intended to limit the scope to the disclosed embodiments, but should be given the widest scope consistent with the principles, features and teachings herein.

[0020] Radio frequency (RF) power modules (such as RF power amplifiers or oscillators) are used as RF generation or amplification stages in RF networks for a variety of applications, including imaging, radar, communications, and others. Millimeter-wave, terahertz, and ultra-high-frequency (UHQF) power modules are needed to achieve high resolution in imaging and radar systems and high data rates in communication systems. High-frequency switching electronic power conditioners offer a compact approach to achieving relatively high output voltages. The combination of high-frequency switching electronic power conditioners with millimeter-wave and up-terahertz vacuum electronics enables the implementation of compact and efficient RF power modules.

[0021] Traditionally, achieving both efficiency and power density simultaneously in electronic power regulators has been challenging (especially in electronic power regulators operating at relatively high voltages (up to 30 kV) and with high efficiency (over 85%). Furthermore, the achievable power density typically decreases as systems operate at lower power levels (e.g., those achievable in millimeter-wave to terahertz vacuum electronics).

[0022] To achieve high efficiency and compact size in electronic power regulators, high-frequency switching power supply topologies can be used. Increasing the frequency switching to levels greater than 1 MHz improves the power density of lower voltage (<1 kV) power converters. This significant increase in frequency allows for a reduction in the value of passive components in the power supply, resulting in a significant reduction in size. For high-voltage electronic power regulators, this is particularly beneficial for magnetic components and output capacitors. Furthermore, the reduction in output capacitance with increasing output voltage reduces the available stored energy in the electronic power regulator and the resulting power module, allowing for safer operation in the event of system failure. The use of resonant inverter-rectifier converter topologies reduces switching losses, achieving both compact and efficient energy conversion.

[0023] To achieve high efficiency in vacuum electronic devices, multi-stage buck current collectors can be used. The electromagnetic design of vacuum electronic devices focuses on utilizing various potential interaction mechanisms between the electron beam and the co-propagating electromagnetic wave. After the interaction between the electron beam and the electromagnetic wave is complete, waste electrons in the electron beam typically exhibit energy diffusion, meaning that waste electrons travel at various speeds. Buck current collectors enable matching the electron potential of the waste electrons, thus "recovering" their kinetic energy back to the power source, rather than converting it into heat. As a result, only the mismatch between the actual electron energy and the electron potential of the individual current collector electrodes is converted into heat. Notably, buck current collectors have been shown to convert electron beam energy back into current with efficiencies up to 99%.

[0024] The number of step-down current collector stages plays a role in the current collector's energy recovery efficiency. Due to the stacked output design of the high-frequency resonant converter technology, the high-frequency switching electronic power conditioner allows for easy access to multiple current collector voltages at various potentials, thereby optimizing the overall system efficiency.

[0025] Figure 1 This is a figure illustrating an RF power module 100 according to some embodiments of the present invention. The RF power module 100 includes a high-frequency switching electronic power conditioner 102 combined with millimeter-wave to terahertz vacuum electronics 104 (e.g., an RF power amplifier or oscillator such as a klystron or traveling-wave tube (TWT)). The vacuum electronics 104 can operate at frequencies between 28 GHz and 280 GHz or at frequencies between 280 GHz and 2.8 THz.

[0026] As shown in the figure, the vacuum electronics 104 includes an electron gun 106 coupled to an interaction structure 112, which in turn is coupled to a buck current collector 114. The electron gun 106 may include a cathode 108 and a cathode heater 110. If the vacuum electronics 104 is a power amplifier, the interaction structure 112 may have both an RF input (RF-In) and an RF output (RF-Out). If the vacuum electronics 104 is an oscillator, the interaction structure 112 may have only an RF output (RF-Out). The buck current collector 114 may have any number (N) of current collector stages, for example, four current collector stages 114a-114d as shown in the figure.

[0027] Regarding voltage, in some embodiments, the electron gun 106 can receive two different voltages, one at the cathode potential and the other at a cathode potential offset by the heater voltage (offset heater voltage). The cathode 108 can receive the cathode voltage. The cathode heater 110 can receive a voltage generated by the cathode voltage and the offset heater voltage. In some embodiments, the cathode heater 110 is a floating voltage referenced to the cathode 108. In some embodiments, additional electrodes are present in the electron gun, with voltages generated by the high-efficiency switching electronic power regulator 102 applied to each electrode. The body of the interaction structure 112 remains at ground potential. Each current collector stage 114a-114d of the buck current collector 114 can operate at different current collector voltages based on the electron potential of the waste electrons that the current collector stages 114a-114d are designed to capture and therefore based on the energy diffusion that the current collector stages 114a-114d are designed to recover. Therefore, the buck current collector 114 can receive N different voltage potentials. The high-frequency switching electronic power regulator 102 is configured to generate the voltage required for the vacuum electronic device 104, which includes a cathode voltage, an offset heater voltage, a ground voltage, and N current collector voltages. In some embodiments, the high-frequency switching electronic power regulator 102 has a stacked arrangement such that the DC output voltages are built up on each other.

[0028] In some embodiments, the cathode 108 is heated by a resistance heater 110. To heat the cathode 108, a cathode voltage is applied to the electrode. Since the heater 110 is close to or electrically connected to the cathode 108, the heater voltage can be configured to "float" on the cathode voltage. Therefore, when the cathode voltage is grounded (i.e., the high cathode voltage is not energized), the heater current will also be close to ground. When the cathode voltage is at its operating voltage, the heater voltage will be close to or reference the cathode operating voltage. In such embodiments, a small voltage (which may be only a few volts) will be used for the heater, which may vary from ground to several or tens of kilovolts. In some embodiments, this is accomplished by causing the high-frequency switching electronic power regulator 102 to implement a heater voltage that is referenced to the cathode voltage (floating on the cathode voltage).

[0029] For communication systems, it is crucial that the output signal of the RF power amplifier faithfully reproduces the input signal (by increasing the amplitude only). If the voltage applied to the electrodes in the vacuum electronics 104 is not sufficiently stable / constant, voltage variations can cause amplitude and / or phase shifts in the output signal. The amplitude shift caused by voltage variations is called the amplitude drive factor. The phase shift caused by voltage variations is called the phase drive factor. The vacuum electronics 104 has associated drive factor requirements for the voltage it receives. In addition to amplitude and phase distortion of the RF output signal, voltage variations can also cause other undesirable effects. For example, if the buck current collector voltage drifts too far, waste electrons may be redirected by electrostatic repulsion. Waste electrons may travel backward, causing undesirable heating and reduced efficiency in the circuit or gun.

[0030] Given the aforementioned problems caused by voltage variations, the high-frequency switching electronic power regulator 102 must be configured to maintain the voltage it provides sufficiently stable within the performance requirements of the vacuum electronics equipment 104. It is worth noting that strictly regulating all voltages to the same tolerance may be impractical, as doing so could result in bulky and / or expensive hardware. Therefore, in some embodiments, the high-frequency switching electronic power regulator 102 may maintain stability of each or a subset of its DC output voltages according to different tolerances. In other embodiments, the high-frequency switching electronic power regulator 102 may maintain stability of some or all DC output voltages according to the same tolerance. The high-frequency switching electronic power regulator 102 may be designed to include individual regulation of each DC output voltage within a specified tolerance, or cross-regulation of some or all DC output voltages within a specified tolerance based on circuit design space.

[0031] In some embodiments, in order to effectively power the vacuum electronic device 104, the high-frequency switching electronic power regulator 102 may meet some or all of the characteristics mentioned in the table below. In some embodiments, the vacuum power device 104 (such as a traveling wave tube) may have the following requirements to achieve overall RF power amplifier performance: To achieve the desired performance characteristics of the RF power module 100, in some embodiments, the high-frequency switching electronic power conditioner 102 and the vacuum electronics 104 can be co-designed. Therefore, sub-component specifications can be developed to ensure that each part meets individual specifications. By understanding the performance requirements and associated voltage sensitivity of the vacuum electronics 104, a high-frequency switching electronic power conditioner 102 that meets the requirements can be developed. Co-developing the high-frequency switching electronic power conditioner 102 and the vacuum electronics 104 allows the entire power module 100 to be optimized as a complete system, enabling the designs of the two components to be customized to work together given the design space for each component.

[0032] Figure 2 This is a diagram illustrating a high-frequency switching electronic power regulator 200 that provides a single direct current (DC) output voltage according to some embodiments of the present invention. In some embodiments, to achieve high efficiency and power density, the high-frequency switching electronic power regulator 200 can be implemented using a high-frequency switching resonant converter topology. The high-frequency switching electronic power regulator 102 can operate in a similar manner to the high-frequency switching electronic power regulator 200, although it has a replication stage to generate multiple DC output voltages. See also... Figure 3A and Figure 3B As an example, and Figure 4A and Figure 4B As another example.

[0033] In some embodiments, the high-frequency switching electronic power conditioner 200 includes a high-frequency inverter 202 coupled to a resonant slot 204, which in turn is coupled to a transformer 206, which in turn is coupled to a resonant rectifier / filter 208. The inverter 202, operating at high frequencies (e.g., >1 MHz), receives a DC input voltage, which, together with the resonant slot 204, converts the voltage and / or current waveforms into sinusoidal variations during one or more sub-intervals in each switching cycle. The sinusoidal waveform allows active components, switches, and rectifiers in the circuit to switch with minimal energy loss during their respective switching transitions. The transformer 206 receives a modified AC square wave from the resonant slot 204 and transforms the voltage of the modified AC square wave based on the number of primary windings relative to the secondary windings. The resonant rectifier / filter 208 receives, rectifies, and filters the voltage-modified AC wave to generate a DC output voltage to power its load. As described above, different portions of the circuit can be replicated (e.g., stacked) to generate multiple DC output voltages.

[0034] The high-frequency switching electronic power conditioner 200 may also include a controller 210, which may compare the DC output voltage with a reference voltage or a reference voltage range and control the high-frequency inverter 202 to adjust its frequency and / or duty cycle, thereby adjusting the DC output voltage as needed. In some embodiments, the controller 210 may be or include a pulse width modulation (PWM) controller that controls the duty cycle of the high-frequency inverter 202 as needed to affect the DC output voltage. The controller 210 may be adjusted to hold the DC output voltage tightly to a specified tolerance. For example, a reference voltage range (e.g., any hysteresis) may be held tight based on a specified tolerance.

[0035] By increasing the frequency of the high-frequency inverter 202 to a frequency of 1 MHz or higher, the size of passive components, including the transformer 206, the resonant tank 204, and the inductors and capacitors in the resonant rectifier / filter 208, is effectively reduced, thereby enabling a reduction in the size of the high-frequency switching electronic power conditioner 200.

[0036] Figure 3A This is a diagram illustrating a high-frequency switching electronic power conditioner 300 with parallel, possibly stacked, resonant rectifiers / filters to generate multiple DC output voltages according to some embodiments of the invention. The high-frequency switching electronic power conditioner 300 can be an example of a high-frequency switching electronic power conditioner 102. The high-frequency switching electronic power conditioner 300 is similar to the high-frequency switching electronic power conditioner 200, except that the transformer 302 includes a plurality (m) of parallel secondary windings, each of which is coupled to a parallel rectifier / filter 304 that generates a corresponding DC output voltage. Each parallel rectifier / filter 304 receives, rectifies, and filters a voltage-corrected AC wave from its parallel secondary winding to generate the corresponding DC output voltage required by the vacuum electronics 104. That is, each parallel resonant rectifier / filter 304 can generate one of a cathode voltage, an offset heater voltage, and N current collector voltages. In some embodiments, the cathode voltage and the offset heater voltage can be generated by the same resonant rectifier / filter 304. In some embodiments, the number of secondary windings in each secondary winding can vary based on the desired DC output voltage. In some embodiments, the circuit components in the parallel resonant rectifier / filter 304 may differ based on the desired DC output voltage. In some embodiments, these two may differ.

[0037] The high-frequency switching electronic power conditioner 300 may also include a controller 306, which may compare the DC output voltage of at least one of the parallel rectifiers / filters 304 relative to a reference voltage or a reference voltage range, and control the high-frequency inverter 202 to adjust inverter characteristics (e.g., its corresponding frequency, phase, and / or duty cycle) to adjust the DC output voltage as needed. In some embodiments, the controller 306 may be or include a pulse width modulation (PWM) controller that controls the duty cycle of the high-frequency inverter 202 as needed to affect the DC output voltage. The controller 210 may be adjusted to tightly maintain the DC output voltage to a specified tolerance. For example, a reference voltage range (e.g., any hysteresis) may be maintained more tightly based on the specified tolerance. In some embodiments, the specified tolerance may be the most stringent tolerance required by the most sensitive voltage of the vacuum electronics 104.

[0038] Figure 3B This is a diagram illustrating a high-frequency switching electronic power conditioner 300 according to some embodiments of the present invention. The high-frequency switching electronic power conditioner 300 includes a high-frequency inverter 202 coupled to a resonant slot 204, which in turn is coupled to a transformer 302, which in turn is coupled to a parallel resonant rectifier / filter 304. The transformer 302 includes a primary winding 352 (which may or may not have a center tap configuration) coupled via a core 356 to secondary windings 354(1)-354(m) (each generally referred to as secondary winding 354) (each of which may or may not have a center tap configuration). Each secondary winding 354(1)-354(m) is coupled to a corresponding resonant rectifier / filter 304(1)-304(m) (each generally referred to as resonant rectifier / filter 304). Each resonant rectifier / filter 304(1)-304(m) generates a corresponding DC output voltage Vdc1-Vdcm.

[0039] Such as about Figure 2Similarly, the inverter 202, operating at high frequencies (e.g., >1MHz), receives a DC input voltage, which, together with the resonant slot 204, converts the voltage and / or current waveforms into sinusoidal variations during one or more sub-intervals in each switching cycle. The sinusoidal waveform allows the active components, switches, and rectifiers in the circuit to switch with minimal energy loss during their respective switching transitions. The transformer 206 receives a modified AC square wave from the resonant slot 204 and transforms the voltage of the modified AC square wave based on the number of secondary windings in the primary winding relative to the number of secondary windings in each corresponding secondary winding 354. Each corresponding resonant rectifier / filter 304 receives, rectifies, and filters its voltage-modified AC wave to generate a corresponding DC output voltage to power its corresponding load. As mentioned above, the number of windings in each secondary winding can vary based on the desired DC output voltage. In some embodiments, the circuitry in the parallel resonant rectifier / filter 304 can vary based on the desired DC output voltage. In some embodiments, both can differ.

[0040] As described above, the high-frequency switching electronic power conditioner 300 may further include a controller 306, which may compare the DC output voltage of at least one of the resonant rectifiers / filters 304 (e.g., resonant rectifier / filter 304(m)) relative to a reference voltage or a reference voltage range, and control the high-frequency inverter 202 to adjust inverter characteristics (e.g., its corresponding frequency, phase, and / or duty cycle) to adjust the DC output voltage as needed. In some embodiments, the controller 306 may be or include a pulse width modulation (PWM) controller that controls the duty cycle of the high-frequency inverter 202 as needed to affect the DC output voltage. The controller 210 may be adjusted to tightly maintain the DC output voltage to a specified tolerance. For example, a reference voltage range (e.g., any hysteresis) may be tightly maintained based on a specified tolerance. In some embodiments, the specified tolerance may be the most stringent tolerance required by the most sensitive voltage requirements of the vacuum electronics 104.

[0041] Figure 4AThis is a diagram illustrating a high-frequency switching electronic power conditioner 400 with parallel power converter stages to generate multiple DC output voltages according to some embodiments of the invention. In some embodiments, the high-frequency switching electronic power conditioner 400 includes a set of parallel high-frequency inverters 402 coupled to a set of parallel resonant tanks 404, which in turn are coupled to a set of parallel transformers 406, which in turn are coupled to a set of parallel rectifiers / filters 408. In other words, the high-frequency switching electronic power conditioner 400 includes several parallel power converter stages, each power converter stage having a corresponding parallel high-frequency inverter 402 coupled to a corresponding resonant tank 404, which in turn are coupled to a corresponding transformer 406, which in turn are coupled to a corresponding resonant rectifier / filter 408. Each power converter stage generates a corresponding DC output voltage (or possibly a subset of DC output voltages), which can be adjusted according to different tolerance levels. In some embodiments, some or all of the groups of parallel resonant rectifiers / filters 408 may be stacked to establish an increased DC output voltage relative to each other in the group.

[0042] In some embodiments, the group of high-frequency inverters 402 receives a DC input voltage. Each inverter 402, operating at a high frequency (e.g., >1 MHz), receives a DC input voltage that, together with the resonant slot 204, converts the voltage and / or current waveform into a sinusoidal variation during one or more sub-intervals in each switching cycle. The sinusoidal waveform allows active components, switches, and rectifiers in the circuit to switch with minimal energy loss during their respective switching transitions. Each transformer 406 receives a modified AC square wave from the associated resonant slot 404 and modifies the voltage of the modified AC square wave based on the number of primary windings relative to the number of secondary windings. Each resonant rectifier / filter 408 receives, rectifies, and filters the voltage-modified AC wave to generate a corresponding DC output voltage to power a corresponding load. In some embodiments, the respective resonant rectifiers / filters 408 may be stacked to establish an increased DC output voltage relative to the floating DC output voltage of the previous resonant rectifier / filter 408 stacked thereon.

[0043] The high-frequency switching electronic power conditioner 400 may also include a set of parallel controllers 410. In other words, each parallel converter stage may have a corresponding controller 410 that may compare its corresponding DC output voltage relative to a corresponding reference voltage or reference voltage range and control the corresponding high-frequency inverter 402 to adjust inverter characteristics (e.g., its corresponding frequency, phase, and / or duty cycle) to adjust the corresponding DC output voltage as needed. In some embodiments, one or more of the controllers 410 may be or include pulse width modulation (PWM) controllers that control the duty cycle of the high-frequency inverter 402 as needed to affect the DC output voltage. By using a separate controller 410 in each converter stage, the corresponding DC output voltage can be kept sufficiently stable according to different tolerance specifications. In some embodiments, only a single controller 410 is required, particularly if the resonant rectifier / filter 408 is stacked, the resonant rectifier / filter 408 is stable, and the specified tolerance requirements are consistent across all DC output voltages.

[0044] Figure 4BThis is a figure illustrating a high-frequency switching electronic power conditioner 400 having parallel power converter stages 460(1)-460(m) (each generally referred to herein as power converter stage 460) to generate multiple DC output voltages according to some embodiments of the invention. The high-frequency switching electronic power conditioner 400 includes several parallel power converter stages 460(1)-460(m), each power converter stage 460 having a corresponding high-frequency inverter 402 coupled to a corresponding resonant slot 404, which in turn is coupled to a corresponding transformer 406, which in turn is coupled to a corresponding resonant rectifier / filter 408. As shown in the figure, the first power converter stage 460 (1) includes a first high-frequency inverter 402 (1) coupled to a first resonant slot 404 (1), which in turn is coupled to a first primary winding 452 (1), which in turn is coupled to a first primary winding 454 (1) of a first transformer 406 via a first core 456 (1), which in turn is coupled to a first resonant rectifier / filter 408 (1). As shown in the figure, the m-th power converter stage 460(m) includes an m-th high-frequency inverter 402(m) coupled to an m-th resonant slot 404(m), which in turn is coupled to an m-th primary winding 452(m), which is further coupled via an m-th core 456(m) to an m-th secondary winding 454(m) of an m-th transformer 406, which in turn is coupled to an m-th resonant rectifier / filter 408(m). Each power converter stage generates a corresponding DC output voltage (or possibly a subset of DC output voltages). In some embodiments, some or all of the groups of resonant rectifiers / filters 408 may be stacked to establish an increased DC output voltage relative to each other within the group.

[0045] In some embodiments, each high-frequency inverter 402(1)-402(m) receives a DC input voltage. Each inverter 402(1)-402(m) operating at high frequencies (e.g., >1MHz) receives a DC input voltage that, together with resonant slots 404(1)-404(m), converts the voltage and / or current waveforms into sinusoidal variations during one or more sub-intervals in each switching cycle. The sinusoidal waveform allows active components, switches, and rectifiers in the circuit to switch with minimal energy loss during their respective switching transitions. Each transformer 406 receives a modified AC square wave from the associated resonant slots 404(1)-404(m) and transforms the voltage of the modified AC square wave based on the number of primary windings in the respective primary windings 452(1)-452(m) relative to the number of secondary windings. Each resonant rectifier / filter 408(1)-408(m) receives, rectifies, and filters a voltage-corrected AC wave to generate a corresponding DC output voltage to power the corresponding load. In some embodiments, the respective resonant rectifiers / filters 408(1)-408(m) may be stacked to establish an increased DC output voltage relative to the floating DC output voltage of the previous resonant rectifier / filter 408(1)-408(m) stacked thereon.

[0046] One, some, or all of the power converter stages 460(1)-460(m) of the high-frequency switching electronic power conditioner 400 may also include a corresponding controller that may compare its corresponding DC output voltage relative to a corresponding reference voltage or reference voltage range and control the corresponding high-frequency inverters 402(1)-402(m) to adjust inverter characteristics (e.g., their corresponding frequency, phase, and / or duty cycle) to adjust the corresponding DC output voltage as needed. In some embodiments, one or more of the controllers 410(1)-410(m) may be or include a pulse width modulation (PWM) controller that controls the duty cycle of the corresponding high-frequency inverters 402(1)-402(m) as needed to affect the DC output voltage. By using a separate controller 410(1)-410(m) in each power converter stage 460, the corresponding DC output voltage can be kept sufficiently stable according to different tolerance specifications. In some embodiments, only a single controller 410 is required, especially if the resonant rectifiers / filters 408(1)-408(m) are stacked, the resonant rectifiers / filters 408(1)-408(m) are stable, and the specified tolerance requirements are consistent across all DC output voltages.

[0047] It should be understood that some embodiments may include Figure 4B The parallel power converter stage shown is, with, as Figure 3B The parallel resonant rectifier / filter 304 shown is combined.

[0048] The use of high-frequency switching allows for smaller, modular power converter stages or modules that can be configured in series and parallel to achieve the design voltage and power handling capacity. This enables modular design that can support the different power amplifier requirements for operating voltage, number of collector stages, and total power levels. The modular approach allows for rapid adaptive adjustments to the design to improve power amplifier operation. Stages can be used in parallel and can be scaled up and down to achieve the desired power amplifier performance as described above. If the vacuum electronics 104 proves to operate better in settings different from the initial design or in different settings for different use cases, the high-frequency switching electronic power conditioner 102 can be quickly reconfigured. These stages can be physical modules manufactured as individual PCB assemblies, or they can be “patterns” used during the design stage and then manufactured as part of a larger PCB assembly.

[0049] Figure 5This is a diagram illustrating a stacked rectifier / filter 408 according to some embodiments of the invention, which stacks corresponding DC output voltages Vdc to power different components of a vacuum electronics device 104. The stacked rectifier / filter 408 may be part of a high-frequency switching electronic power conditioner 300 or a switching electronic power conditioner 400. More specifically, a first rectifier / filter 408 (1) may generate a ground potential for the interacting structure 112 and a first DC output voltage Vdc (1) to power a first current collector stage 114 (a). A second rectifier / filter 408 (2) may generate a second DC output voltage Vdc (2) floating above the first DC output voltage Vdc (1), thereby powering a second current collector stage 114 (b). A third rectifier / filter 408 (3) may generate a third DC output voltage Vdc (3) floating above the second DC output voltage Vdc (2), thereby powering a third current collector stage 114 (c). A fourth rectifier / filter 408 (4) can generate a fourth DC output voltage Vdc (4) floating above the third DC output voltage Vdc (3), thereby powering the fourth current collector stage 114 (d). A fifth rectifier / filter 408 (5) can generate a fifth DC output voltage Vdc (m) floating above the fourth DC output voltage Vdc (4), thereby powering the cathode 108. A sixth rectifier / filter 408 (6) can generate a sixth DC output voltage Vdc (6) floating above the fifth DC output voltage Vdc (5), thereby powering the cathode heater 110. Other embodiments are possible. For example, in some embodiments, fewer or additional current collector stages may be present. In some embodiments, a single rectifier / filter 408 can generate multiple voltages to power multiple components of the vacuum electronics 104.

[0050] In some embodiments, at high voltages (constant DC with low ripple), cathode regulation needs to be quite stringent to achieve low spurious distortion of the RF signal. Body current is the current flowing from the cathode to ground (not to the current collector). Body current is affected by the RF input signal, and therefore it is a variable load on the cathode voltage generation system. To prevent current backflow from the current collector, the current collector electrode voltage must be kept stable in the presence of dynamically changing loads (i.e., the current flowing to the current collector stage is determined by the applied RF signal). For the current collector, the operating conditions change significantly from no RF output to full saturation RF output operation—meaning the power supply experiences varying loads at each electrode. Since these variations can occur at RF frequencies, the load can change rapidly. The power supply design must be adapted to maintain regulation in the presence of these rapidly changing loads.

[0051] The design of the high-frequency switching electronic power regulator 102 is influenced by the design of the vacuum electronics 104, which in turn affects efficiency and overall prime power. Efficiency and size are affected by design quality, so ensuring that only necessary design details are implemented is crucial for a fast design cycle. Three-way optimization can be performed on size, power (efficiency), and performance.

[0052] As electrons leave the cathode, they carry heat, which cools the cathode. The performance of the cathode (in terms of its ability to generate the required current) depends on controlling the temperature. When the vacuum electronics 104 operates at a higher duty cycle (up to CW), the heater power needs to be increased to maintain the cathode at the design temperature, thereby providing the required cathode current. The power module can incorporate various methods to maintain the temperature. In one embodiment, a lookup table or analog circuitry is used to adjust the heater power based on the duty cycle the cell is operating at. In another embodiment, the cathode current is sensed, and a feedback loop is used to control the heater power to keep the emitted cathode current within the desired range.

[0053] Noise power is a critical characteristic of RF power amplifiers because it limits the achievable signal-to-noise ratio, thus limiting the total data rate achievable through a communication system. One metric is the error vector magnitude, which characterizes the error in the constellation plot when the communication system processes the waveform. RF noise is influenced by electronic noise on the cathode voltage and noise (shot noise, etc.) within the vacuum electronics 104. Achieving the required RF performance is proportional to the permissible noise within the vacuum electronics 104.

[0054] For power amplifiers using configurations without control electrodes in the gun, the amplifier does not need a module to turn the beam on and off, which is common in conventional vacuum electronics power supplies. This makes the entire system more compact (eliminating the need for a mod anode or beam modulator / grid / aperture grid). Particularly for these amplifiers, the vacuum electronics 104 and the high-frequency switching electronic power conditioner 102 must operate under conditions beyond the nominal conditions during on- and off. At low cathode voltages, the vacuum electronics 104 may have poor beam transmission, so the system will run through a high volume current cycle during the on- and off transients. This could damage the vacuum electronics 104, or it could damage the high-voltage switching electronic power conditioner 102, or it could cause the high-voltage switching electronic power conditioner 102 to self-protect by entering a fault state. Each of these results is undesirable in terms of the ability to cope with the system. Designers must ensure that the combination of the rise and fall times of the output voltage of the high-voltage switching electronic power regulator 102 and the thermal robustness of the vacuum electronics 104 is survive of transient conditions during turn-on and turn-off. Designers must also ensure that the protection circuitry of the high-voltage switching electronic power regulator 102 is configured to allow the unit to "pass through" turn-on transient power surges (if they exceed protection limits for a short period of time).

[0055] The high-frequency switching electronic power regulator 102 must be able to survive electric arcs in the vacuum electronics 104, from any electrode to any electrode or from any electrode to ground. Furthermore, the high-frequency switching electronic power regulator 102 must ensure that the vacuum electronics 104 is not damaged by an arcing event. In some configurations, this may require a fast protection circuit designed to remove voltage upon detection of an arc. In other embodiments, this may involve selections regarding the amount of stored energy available to supply the arc, the location and manner in which the stored energy dissipates throughout the arc path, and slower protection circuitry.

[0056] Throughout this specification, multiple instances may be implemented as components, operations, or structures described as a single instance. While individual operations of one or more methods are shown and described as separate operations, one or more of these individual operations may be performed simultaneously, and it is not required that they be performed in the order shown. Structures and functions presented as separate components in the example configuration may be implemented as combined structures or components. Similarly, structures and functions presented as single components may be implemented as separate components. These and other variations, modifications, additions, and improvements fall within the scope of this document's subject matter.

[0057] The above description of preferred embodiments of the present invention is merely illustrative, and other variations and modifications of the above embodiments and methods are possible based on the above teachings. The embodiments described herein are not intended to be exhaustive or limiting. The invention is limited only by the appended claims.

Claims

1. A power module comprising: a high frequency switching electronic power regulator including stacked resonant rectifiers / filters that generate stacked DC output voltages; and a vacuum electronic device coupled to the high frequency switching electronic power regulator, the vacuum electronic device including components that each receive a respective one of the stacked DC output voltages.

2. The power module of claim 1, wherein the high frequency switching electronic power regulator has a switching frequency higher than 1 MHz.

3. The power module of claim 1, wherein the vacuum electronic device operates at frequencies between 28 GHz and 280 GHz.

4. The power module of claim 1, wherein the vacuum electronic device operates at frequencies between 280 GHz and 2.8 THz.

5. The power module of claim 1, wherein the high frequency switching electronic power regulator employs a resonant topology.

6. The power module of claim 1, wherein the components include a set of voltage- reduced collector stages, and wherein the stacked DC output voltages include a set of DC output voltages for the set of voltage-reduced collector stages.

7. The power module of claim 1, wherein the components include a cathode and a cathode heater, and wherein the stacked DC output voltages include a cathode voltage and a cathode heater voltage.

8. The power module of claim 1, wherein the cathode heater voltage is referenced to the cathode voltage.

9. The power module of claim 1, wherein the high frequency switching electronic power regulator includes a high frequency inverter; a resonant tank; a transformer coupled to the resonant tank and to the set of stacked resonant rectifiers / filters; and a controller configured to control characteristics of the high frequency inverter to control the DC output voltages according to specified tolerances.

10. The power module of claim 9, wherein the controller includes pulse width modulation that controls a duty cycle of the high frequency inverter.

11. The power module of claim 9, wherein the transformer includes a primary winding and a set of secondary windings, each coupled to a respective one of the stacked rectifiers / filters.

12. The power module of claim 1, wherein the components include a cathode, a cathode heater, and a set of voltage-reduced collector stages.

13. The power module of claim 1, wherein the high frequency switching electronic power regulator has a set of two or more power converter stages, each power converter stage including a high frequency inverter; a resonant tank; and a transformer coupled to the resonant tank and to a respective one of the stacked resonant rectifiers / filters.

14. The power module of claim 13, wherein each power converter stage has a controller configured to control characteristics of the high frequency inverter to control the respective DC output voltage of the power converter stage. ​ ​ ​ 15. The power module of claim 14, wherein at least one controller of at least one power converter stage comprises a pulse width modulation that controls a duty cycle of the high frequency inverter of the power converter stage.

16. The power module of claim 13, wherein the controller is configured to control stability of the respective DC output voltage to a specified tolerance.

17. The power module of claim 13, wherein a particular power converter stage is configured to generate at least two DC output voltages, and wherein the controller is configured to control stability of the at least two DC output voltages to a specified tolerance.

18. The power module of claim 13, wherein the transformer comprises a primary winding and a secondary winding, the secondary winding coupled to a respective one of the stacked resonant rectifiers / filters.

19. The power module of claim 13, wherein a particular power converter stage has a controller configured to control a characteristic of the high frequency inverter to control the respective DC output voltage of the particular power converter stage.

20. The power module of claim 19, wherein the controller is configured to control stability of the respective DC output voltage to a specified tolerance.

Images