58 results about "Balanced amplifier" patented technology

A hybrid coupler has a first port, a second port, a third port, and a fourth port to which a load is connected. An input signal distributor distributes a first input signal that is a radio frequency signal into a second input signal and a third input signal. The second input signal is inputted to a balanced amplifier. The balanced amplifier outputs two amplified radio frequency signals with a phase difference of 90° from each other from two output ends, one of which is coupled to the first port and another one of which is coupled to the second port. The control amplifier amplifies the third input signal and outputs the amplified third input signal from an output end. The output end of the control amplifier is coupled to the third port without any circuit component affecting impedance matching disposed in between.

A hybrid coupler-based T / R switch for use in a TDM system. An output hybrid coupler of a balanced amplifier is used to selectively switch a transmit or receive path to an antenna. During transmission, power at the output of the balanced amplifier is delivered directly to the antenna. During reception, power from the antenna is reflected through ports of the hybrid coupler connected to respective two amplifiers of the balanced amplifier, to constructively combine at a port of the coupler coupled to the receive path, with a ninety degrees phase shift. A pair of shunting switches or series switches coupled to the ports of the hybrid coupler connected to the two amplifiers, and a shunting switch coupled to the port coupled to the receive path, control operation of the hybrid coupler-based T / R switch. An additional switch coupled to the port of the coupler that is coupled to the receive path can provide a bypass path for reception or transmission through the antenna while bypassing the balanced amplifier of the transmit path and an amplifier of the receive path.

Provided is a single differential-based balanced amplifier including one differential amplifier configured to receive a first differential input signal and a second differential input signal having a phase difference of 180 degrees from the first differential input signal, and output a first differential output signal at a first output terminal and a second differential output signal at a second output terminal, a phase delay circuit configured to receive the first differential output signal, and output a third differential output signal obtained by adjusting a phase of the first differential output signal relative to the second differential output signal by 90 degrees, and a hybrid coupler configured to receive the second differential output signal at a first port, receive a third differential output signal at a third port, and output, at a second port, an in-phase signal in which RF power of the second differential output signal and the third differential output signal are combined in phase.

A method includes providing a first power from an output terminal of a balanced amplifier to a discharge chamber. The balanced amplifier includes two amplifier paths, each of which supplies a signal to a coupler. The coupler is configured to combine the signals as a function of their phase relationship and supply a power as the first power to the output terminal and / or as a second power to an isolation terminal. The method further includes setting a first phase relationship between the signals for a predefined time in order to ignite the plasma, and setting a second phase relationship in order to maintain the plasma. Under the second phase relationship, substantially an entirety of the power is supplied to the output terminal. Under the first phase relationship, a third power reflected from the discharge chamber is reflected back to the discharge chamber in a proportion large enough for the ignition.

This invention provides an unmanned aerial vehicle (UAV) image transmission system and image transmission method. The system includes: a radio frequency (RF) transceiver, a balanced amplifier circuit, a low-noise amplifier, and an RF switch. The balanced amplifier circuit includes at least two parallel power amplifiers configured to superimpose the amplified signals from each power amplifier in phase to synthesize the output power. The RF transceiver generates a time-division duplex control signal to synchronously control the switching of each component between transmit and receive modes. By employing a balanced amplifier circuit, this invention enables each power amplifier to operate in a region with better linearity, thereby improving transmit power while ensuring the signal quality required for high-order modulation, thus balancing long-distance transmission and high-definition image quality.

The invention provides a high-frequency power amplifier which can realize miniaturization and broadband. The input signal distributor distributes a high-frequency first input signal into a second input signal and a third input signal. A second input signal is input to the balanced amplifier. And two output ends of the balanced amplifier for outputting two amplified high-frequency signals with a phase difference of 90 degrees are respectively coupled with the first port and the second port. And the control amplifier amplifies the third input signal and outputs the amplified signal from the output end. The output of the control amplifier is coupled to the third port without via a circuit component that affects impedance matching. The balanced amplifier and the control amplifier are supplied with a common power supply voltage. The voltage level of the first input signal when the current output from the control amplifier rises is higher than the voltage level of the first input signal when the current output from the balance amplifier rises. The hybrid coupler varies a load impedance of a balanced amplifier coupled to the first and second ports in accordance with a current level of a high-frequency signal input from the control amplifier to the third port.

Example embodiments relate to pseudo-Doherty load modulated balanced amplifiers, PD-LMBAs. One example PD-LMBA is configured to operate in a given frequency band. The PD-LMBA includes a main splitter for splitting an input RF signal into a first signal and a second signal, a main amplifier for amplifying the first signal, a balanced amplifier for amplifying the second signal, and a phase offset unit. The balanced amplifier includes a splitter for splitting the second signal into a first part and a second part of the second signal, a first amplifier and a second amplifier for amplifying the first part of the second signal and the second part of the second signal, respectively, and a combiner. The phase offset unit includes at least one shunt series circuit connected to ground and at least one parallel resonance circuit arranged in between an input and an output of the phase offset unit.

The present application relates to a pseudo-Doherty load modulated balanced amplifier (PD-LMBA), and to a mobile communication base station comprising the PD-LMBA. The present application relates to a load modulated balanced amplifier (PD-LMBA) and to a mobile communication base station comprising the PD-LMBA. According to the invention, the PD-LMBA comprises a phase offset unit comprising at least one shunt series circuit connected to the ground, each shunt series circuit comprising an impedance transformer and a termination circuit arranged between the impedance transformer and the ground, the termination circuit is configured to present an RF short circuit to the impedance transformer at a first frequency within or near the frequency band, where the impedance transformer is configured to transform the RF short circuit to an RF open circuit at the first frequency. The phase offset unit further comprises at least one parallel resonant circuit arranged between the input and the output of the phase offset unit, where an impedance of the at least one parallel resonant circuit corresponds to an RF open circuit at a second frequency outside the frequency band. The first frequency is closer to a center frequency of the frequency band than the second frequency.

A hybrid coupler-based T / R switch for use in a TDM system. An output hybrid coupler of a balanced amplifier is used to selectively switch a transmit or receive path to an antenna. During transmission, power at the output of the balanced amplifier is delivered directly to the antenna. During reception, power from the antenna is reflected through ports of the hybrid coupler connected to respective two amplifiers of the balanced amplifier, to constructively combine at a port of the coupler coupled to the receive path, with a ninety degrees phase shift. A pair of shunting switches or series switches coupled to the ports of the hybrid coupler connected to the two amplifiers, and a shunting switch coupled to the port coupled to the receive path, control operation of the hybrid coupler-based T / R switch. An additional switch coupled to the port of the coupler that is coupled to the receive path can provide a bypass path for reception or transmission through the antenna while bypassing the balanced amplifier of the transmit path and an amplifier of the receive path.

A power amplifier and a method of controlling a power amplifier are described. The power amplifier (300) comprises a hybrid combiner (310) comprising a first input port and a second input port, an isolated port and an output port, wherein the hybrid combiner (310) delivers an output power at the output port. A balanced amplifier arrangement (320) is comprised, the balanced amplifier arrangement (320) comprising a main amplifier arrangement, a first peaking amplifier and a second peaking amplifier, wherein the output of the main amplifier arrangement and the outputs of the first and second peaking amplifiers are coupled to the first and second input ports of the hybrid combiner (310) to provide the output power at the output port. A third peaking amplifier (330) has an output coupled to the isolated port of the hybrid combiner (310). A peaking signal distribution circuit distributes a peaking amplification signal to the input ports of the first, second and third peaking amplifiers.

The invention relates to a load modulation balanced power amplifier with low loss and high rollback efficiency, and the power amplifier comprises a signal distribution module which is used for dividing an input signal into three paths of signals; the control power amplifier module is used for amplifying the first path of signals and outputting the signals through a 3dB quadrature coupler of the balance power amplifier module before the amplitudes of the second path of signals and the third path of signals reach threshold values respectively; after the amplitudes of the second path of signal and the third path of signal respectively reach threshold values, inputting the amplified first path of signal into a balanced amplifier module so as to control the output impedance of the balanced amplifier module; and the balanced power amplifier module is used for amplifying the second-path signal and the third-path signal with different amplitudes and phases after the amplitudes of the second-path signal and the third-path signal respectively reach threshold values, and coupling and outputting the first-path signal, the second-path signal and the third-path signal through a 3dB orthogonal coupler.

To improve the power efficiency of a power amplifier.SOLUTION: The power amplifier 100,101 includes a balanced amplifier BA and a control amplifier 5. The balanced amplifier BA includes a first amplifier 1 and a second amplifier 2 that amplify input power. A load modulation balanced amplifier is formed by a control amplifier 5 and a balanced amplifier BA and a control signal including a harmonic component of input power is fed to the balanced amplifier BA. The control amplifier 5 is a class AB amplifier or a class B amplifier. Each of the first amplifier 1 and the second amplifier 2 is a class C amplifier.SELECTED DRAWING: Figure 2

A power amplifier includes a balanced type amplifier and a control amplifier. The balanced type amplifier includes a first amplifier and a second amplifier and is configured to amplify an input power. The control amplifier is configured to form a load modulated balanced amplifier together with the balanced type amplifier and output a control signal including a fundamental wave component or a harmonic component of the input power to each of the first amplifier and the second amplifier. The control amplifier is disposed between the first amplifier and the second amplifier.

The invention provides an emission driving system and nuclear magnetic resonance equipment, and relates to the technical field of magnetic resonance. The emission driving system comprises a load modulation balance amplifier, a switching module and a control module. The first end of the load modulation balance amplifier is connected with the body coil; the first end of the switching module is connected with the second end of the load modulation balanced amplifier, the second end of the switching module is connected with the third end of the load modulation balanced amplifier, and the third end of the switching module is connected with the local coil; the control module is configured to control the switching module to be in the first conduction state or the second conduction state. The emission driving system aims at solving the problems that in the prior art, the cost of a body coil and local coil emission mode switching scheme of magnetic resonance imaging equipment is high, and the size is large due to the fact that a power amplifier cannot be reused.

The present application relates to the technical field of radio frequency chip power amplifiers, and specifically to a high-gain load-modulated balanced amplifier, comprising: an RF input connected to the input end of a power divider, a first output end of the power divider connected to the input end of a phase shifter, a second output end of the power divider connected to the input end of an input coupler, an output end of the phase shifter connected to a control power amplifier, and an output end of the control power amplifier connected to an isolation end of the input coupler; a through-end of the input coupler connected to the input end of a first sub-balanced amplifier, a coupling end of the input coupler connected to the input end of a second sub-balanced amplifier, and an output end of the first sub-balanced amplifier connected to a coupling end of an output coupler; an output end of the second sub-balanced amplifier connected to a through-end of an output coupler; an isolation end of an output coupler connected to a reactance load, the other end of the reactance load being grounded; and an input end of the output coupler connected to an RF output, so that only a very low-power control signal is required to meet the requirements.

The invention provides an active load modulation balanced radio frequency power amplifier. The active load modulation balanced radio frequency power amplifier comprises a high-pass filter, a phase shifter and an attenuator, the isolation end of the output 3dB coupler is sequentially connected with a high-pass filter, a phase shifter and an attenuator; the output end of the attenuator is respectively connected with the two input matching networks; the two input matching networks are connected with the input 3dB coupler and the group of balanced power amplifiers. According to the application, the characteristics of an active load modulation balanced amplifier are utilized, fundamental waves and second harmonics are isolated through the high-pass filter, the phase of the second harmonics is adjusted through the phase shifter, the amplitude of the second harmonics is adjusted through the attenuator, then the second harmonic signals are injected into the power amplifier, active devices are not needed in the harmonic injection process, and the harmonic injection efficiency is improved. The harmonic injection circuit is realized only by using a low-cost passive circuit, so that the cost is effectively reduced, and the circuit area is reduced.

According to an aspect of the present disclosure, the balanced amplifier of the PD-LMBA module comprises one or more first semiconductor dies mounted on the substrate and on which a first power transistor and a second power transistor are integrated. The balanced amplifier further comprises a first matching network, a second matching network, and a transmission line-based directional coupler. The first and second matching network each comprise a shunt capacitive element of which a non-grounded terminal is connected to the relevant port of the directional coupler and a connection connecting the output of the relevant power transistor to this port.

This power amplifier is provided with a carrier amplifier module (5), a balanced amplifier module (4), a first delay line (80), and a second delay line (81). The thermal resistance in the first amplifier (10) from the active element (12) to the back side of the package is less than the thermal resistance from the active element (22) of the second amplifier (20) and the active element (32) of the third amplifier (30) to the back side of the package. The sum of the electrical length from the input terminal (2) to the first internal output terminal (90) and the electrical length from the first internal input terminal (91) to the output terminal (3) is equal to the sum of the electrical length from the input terminal (2) to the second internal output terminal (92) and the electrical length from the second internal input terminal (93) to the output terminal (3). The first delay line (80) and the second delay line (81) have the same electrical length.

Balanced topology multi-signal duplex synthesis and power amplifier and amplification method based on, belong to communication technical field, include: the two ports of the input side of first stage 90 DEG electric bridge receive a frequency point signal respectively, the two ports of the output side of first stage 90 DEG electric bridge are connected the input end of two power amplifiers of two branches respectively, and the output end of two amplifiers is connected to the two ports of the input side of secondary 90 DEG electric bridge respectively.The present application has the advantages of balanced amplifier power synthesis and high stability, and also has the function of double-band signal duplex synthesis and power amplifier, avoids the problem of amplifier gain decline caused by the insertion loss of duplexer or combiner.Compared with the traditional balanced amplifier, the method realizes duplex synthesis, filtering and power amplification with extremely simple topology, effectively improves the efficiency of the amplifier, and effectively reduces the number of hardware and improves the performance of the amplifier.

The present application relates to a pseudo-Doherty load modulated balanced amplifier, PD-LMBA, and a mobile radio base station comprising the same. According to the present invention, the PD-LMBA comprises a phase offset unit comprising at least one shunt series circuit connected to ground, each shunt series circuit comprising an impedance inverter and a termination circuit arranged between the impedance inverter and ground, the termination circuit being arranged to present an RF short circuit to the impedance inverter at a first frequency that is within or near the frequency band, the impedance inverter being arranged to convert the RF short circuit into an RF open circuit at the first frequency. The phase offset unit further comprises at least one parallel resonant circuit arranged between an input and an output of the phase offset unit, wherein an impedance of the at least one parallel resonant circuit corresponds to an RF open circuit at a second frequency that lies outside the frequency band. The first frequency is closer to a center frequency of the frequency band than the second frequency.

A compact, broadband, transformer-based Quadrature Hybrid Coupler (QHC) (34) exhibits improved gain and phase imbalance over a broadband frequency range, compared to conventional QHCs (30) The QHC (34) comprises a combination of a conventional transformer- based QHC (30) and a constant-R bridged-T all pass delay element (32). The QHC (34) operates as a 90° phase shift splitter and combiner. Applications of the QHC (34) include balanced amplifiers and Load Modulated Balanced PAs (LMBA). The constant-R network provides a discrete equivalent of a wideband dispersion free transmission line, increasing the QHC (34) bandwidth. It introduces a constant phase delay for all frequencies. More than a mere combination of these two circuits, however, the inventive QHC (34) merges several of the passive elements (inductors / transformers) to reduce component count, and some capacitors are placed conveniently at the center of the transformer, resulting in a compact, broadband QHC (34).

The invention discloses a bidirectional amplifier structure with a low noise coefficient and high output power. According to the amplifier, the functions of a power amplifier and a low noise amplifier in a duplex system are realized by utilizing the structure of a load modulation balanced amplifier. Multiple coupling transformers are introduced into a control circuit input and output matching network, so that redundant loss caused by a quadrature coupler is avoided, and excellent noise coefficient and gain performance of an LNA mode are realized under the condition of ensuring high output power and high efficiency of a PA mode. According to the circuit, the input / output network of a control circuit is improved on the basis of the original architecture, so that better performance of the bidirectional amplifier is realized.

A method and apparatus are disclosed for providing therapeutic electric current to a treatment site of a patient. The steps of the method comprise generating a first and second signal having a frequency difference between 1 Hz and 300 Hz, wherein each signal has a frequency of at least 1 KHz and are amplified by Class D switching amplifiers, minimizing the DC component of the first and second signals using balanced amplifiers; operatively coupling a first electrode of at least one pair of electrodes to a patient's body on or beneath a first epidermal or mucous membrane surface; operatively coupling a second electrode of at least one pair of electrodes to a patient's body on or beneath a second epidermal or mucous membrane surface; forming a therapeutic signal configured to reduce pain at a treatment site by simultaneously sending a first signal from the first electrode to the second electrode and sending a second signal from a second electrode to the first electrode, and then simultaneously sending the first signal from the second electrode back to the first electrode and the second signal from the first electrode back to the second electrode, wherein the first and second signals are linearly independent off phase alternating current signals; and adjusting the therapeutic signal utilizing a feedback system based on impedance changes within the patient's body.

A parallel e-fuse device including: a first e-fuse to receive an input voltage and transfer a first fuse current to an output terminal; and a second e-fuse to receive the input voltage and transfer a second fuse current to the output terminal, the first e-fuse includes: a power transistor to control the first fuse current according to a gate voltage; a clamp amplifier to provide a charging current to charge a gate of the power transistor, the charging current being obtained by monitoring a feedback voltage; a balance amplifier to provide a first sinking current to discharge the gate of the power transistor, the first sinking current being obtained by comparing a current sensing signal with a current monitoring signal, wherein the clamp amplifier generates the charging current according to a differential voltage between the feedback voltage and a reference voltage.

Aspects of this disclosure relate to a multi-stage pseudo-Doherty load modulated balanced amplifier that includes a control stage and balanced stages. The balanced stages can each include a balanced amplifier biased in class C. The balanced stages can each include an output coupler having a port driven by another stage of the multi-stage pseudo-Doherty load modulated balanced amplifier. In certain embodiments, two or more stages of the multi-stage pseudo-Doherty load modulated balanced amplifier are driven by separate drive signals.

The present invention discloses a broadband load modulation balanced amplifier with harmonic suppression function. The power amplifier is characterized by the use of a dual transmission line bandpass matching circuit. In the target design frequency band, this structure can achieve broadband matching of the optimal complex impedance of the power amplifier, and insert multiple transmission zeros in the second and third harmonic frequency bands to achieve the effect of suppressing harmonics. The circuit consists of ten sections of transmission lines, namely, pads, two groups of dual transmission lines on the main transmission path, two half-wavelength stub transmission lines connected in parallel at the same node, a stepped stub transmission line located between the two groups of dual transmission lines, and a quarter-wavelength stub transmission line grounded. The power amplifier proposed by the present invention is a broadband load modulation balanced amplifier with harmonic suppression function, which is applicable to the broadband and multi-band application scenarios of communication systems and can meet their requirements for communication bandwidth and linearity.

A multiple-mode RF power amplifier includes two power amplifiers, output combiner circuitry, and a switchable impedance circuit. The power amplifiers receive first and second input RF signals and produce first and second amplified RF signals. The output combiner circuitry combines the amplified RF signals to produce a combined amplified RF signal. The switchable impedance circuit has an input terminal coupled to an isolated port of the output combiner circuitry. When the switchable impedance circuit is in a first state, the isolated port is coupled through the switchable impedance circuit to a first impedance to configure the multiple-mode RF power amplifier as a balanced amplifier. When the switchable impedance circuit is in a second or third state, the isolated port is coupled through the switchable impedance circuit to a second or third impedance to configure the multiple-mode RF power amplifier as a first or second type of Doherty power amplifier.

The invention relates to a power amplifier. The power efficiency of the power amplifier is improved. A power amplifier (100, 101) is provided with a balanced amplifier (BA) and a control amplifier (5). A balanced amplifier (BA) includes a first amplifier (1) and a second amplifier (2) that amplify input power. The control amplifier (5) forms a load modulation balanced amplifier together with the balanced amplifier (BA), and supplies a control signal including a harmonic component of the input power to the balanced amplifier (BA). The control amplifier (5) is a class AB amplifier or a class B amplifier. The first amplifier (1) and the second amplifier (2) are respectively class-C amplifiers.

The invention discloses a low-temperature-drift-coefficient voltage reference source with load driving capacity. The low-temperature-drift-coefficient voltage reference source comprises a temperature negative correlation circuit, an unbalanced amplifier, a time domain amplifier and a voltage superposition main branch. According to the invention, the temperature negative correlation circuit and the improved unbalanced amplifier are combined, so that the nonlinear term related to the temperature in the output voltage is greatly reduced, a very small temperature coefficient is achieved, and an additional starting circuit is not needed. In addition, by adopting the stacked NMOS structure, the output voltage is effectively reduced along with process deviation; by adopting the time domain amplifier, high gain, low power consumption and 20mA load driving capability are realized under the lowest low power supply voltage of 0.9 V.

The utility model provides a radio frequency power amplification circuit based on a balanced power amplification structure, which comprises a first orthogonal coupler, a second orthogonal coupler, a third orthogonal coupler and a fourth orthogonal coupler, the first balance amplification module receives one path of orthogonal radio frequency signal and outputs a first amplification signal; the second balance amplification module is used for receiving the other path of orthogonal radio frequency signal and outputting a second amplification signal; a second quadrature coupler receiving the first amplified signal and the second amplified signal which are orthogonal and generating a single-ended radio frequency output; wherein the first quadrature coupler comprises an input transformer comprising a first winding and a second winding, an input capacitor and an input resistor, the first winding is connected between the single-ended radio frequency input and the input end of the first balanced amplification module, and the input capacitor is connected between the single-ended radio frequency input and the input end of the second balanced amplification module. One end of the second winding is connected between the input capacitor and the input end of the second balance amplification module, and the other end of the second winding is grounded through the input resistor.