Abstract: A power amplifier module includes an amplifier that amplifies an input signal and outputs the amplified signal, a harmonic termination circuit that is disposed subsequent to the amplifier and that attenuates a harmonic component of the amplified signal, the harmonic termination circuit including at least one field effect transistor (FET), and a control circuit that controls a gate voltage of the at least one FET to adjust a capacitance value of a parasitic capacitance of the at least one FET. The control circuit adjusts the capacitance value of the parasitic capacitance of the at least one FET, and thereby a resonance frequency of the harmonic termination circuit is adjusted.

Abstract: An amplifier for a receiver circuit is disclosed. The amplifier has an input node (Vin) and an output node (Vout). It comprises a tunable tank circuit connected to the output node (Vout), a feedback circuit path connected between the output node (Vout) and the input node (Vin), and a tunable capacitor connected between an internal node of the feedback circuit path and a reference-voltage node. A receiver circuit and a communication apparatus is disclosed as well.

Abstract: A circuit includes an amplifier to amplify an input signal and generate an output signal. The circuit also includes a tuning network to tune frequency response of the amplifier. The tuning network includes at least one tunable capacitor, which includes at least one micro-electro mechanical system (MEMS) capacitor. The amplifier could include a first die, the at least one MEMS capacitor could include a second die, and the first die and the second die could be integrated in a single package. The at least one MEMS capacitor could include a MEMS superstructure over a control structure, which is to control the MEMS superstructure and tune the capacitance of the at least one MEMS capacitor.

Abstract: The operative bandwidth of a broadband RF amplifier is improved by using a low-pass type broadband impedance transformer, instead of a broadband matching network, in a multi-stage impedance matching network connected, e.g., to the amplifier input. The multi-stage impedance matching network comprises three stages connected in series. The first stage is a low-pass type broadband impedance transformer that provides broadband fundamental impedances and high reflection for the second harmonics. The second stage is a phase shifter that controls the location of the second harmonic reflection coefficient phases. The third stage is a high-pass input matching circuit that transforms the complex conjugate device input impedance to a real impedance.

Abstract: A receiver front end having low noise amplifiers (LNAs) with enhanced input third order intercept point is disclosed herein. A cascode having a “common source” configured input FET and a “common gate” configured load FET have a degeneration circuit comprising a tank circuit tuned to a harmonic of the operating frequency.

Abstract: A power amplifier module includes a first amplifier that amplifies an input signal to generate a first amplified signal and outputs the first amplified signal, a second amplifier that amplifies the first amplified signal to generate a second amplified signal and outputs the second amplified signal, and a matching network disposed between an output terminal of the first amplifier and an input terminal of the second amplifier. The first amplifier is provided on a first chip, and the second amplifier is provided on a second chip. The matching network has an impedance transformation characteristic adjustable in accordance with a control signal.

Abstract: The present disclosure provides a microwave oven, and a thawing control method and device for the same. The method includes: acquiring a total period T of thawing according to a weight x of food in the microwave oven, wherein the total period T of thawing satisfies: T=K(x/100) seconds, where, 20 seconds/g?K?120 seconds/g; and controlling the microwave generator to start, and thawing the food according to the total period T of thawing. With the method, the thawed food is more nutritious, healthier, and easier to cut, and has the low temperature difference, without a cooked discoloration phenomenon.

Abstract: Provided is an electric transmission cable module that has both a squelch function and an AGC function, and realizes a highly accurate function while suppressing an increase in chip cost.

Abstract: An improved architecture for a radio frequency (RF) power amplifier, impedance matching network, and selector switch. One aspect of embodiments of the invention is splitting the functionality of a final stage impedance matching network (IMN) into two parts, comprising a base set of off-chip IMN components and an on-chip IMN tuning component. The on-chip IMN tuning component may be a digitally tunable capacitor (DTC). In one embodiment, an integrated circuit having a power amplifier, an on-chip IMN tuner, and a selector switch is configured to be coupled to an off-chip set of IMN components. In another embodiment, an integrated circuit having an on-chip IMN tuner and a selector switch is configured to be coupled through an off-chip set of IMN components to a separate integrated circuit having an RF power amplifier.

Abstract: An amplifier circuit for amplifying an input signal includes a transistor configured to receive the input voltage via an input port, and a second-harmonic trap connected between the transistor and ground, the second-harmonic trap having an impedance high enough to enable the second-harmonic trap to act as an open circuit at a second harmonic frequency of a voltage provided by the transistor. The second-harmonic trap includes a transformer including a primary winding connected to ground and a secondary winding, the primary winding receiving the voltage provided by the transistor. The second-harmonic trap further includes a variable capacitor connected in parallel with the secondary winding of the transformer, the variable capacitor having an adjustable capacitance that may be adjusted for the second-harmonic trap to act as the open circuit at the second harmonic frequency.

Abstract: A power amplification module includes: an amplifier that amplifies an input signal and outputs an amplified signal; and a harmonic-termination circuit to which harmonics of the amplified signal are input and the impedance of which is controlled in accordance with the frequency of a harmonic. The power amplification module can operate in a first mode in which a power supply voltage changes in accordance with the average voltage value of the amplified signal over a prescribed time period or in a second mode in which the power supply voltage changes in accordance with the envelope of the input signal. The impedance of the harmonic-termination circuit is controlled such that at least one even-ordered harmonic is short-circuited when the power amplification module operates in the first mode and at least one odd-ordered harmonic of third order or higher is short-circuited when the power amplification module operates in the second mode.

Abstract: An amplifier for converting a single-ended input signal to a differential output signal. The amplifier comprises a first transistor, a second transistor, a third transistor and a fourth transistor. The first transistor, configured in common-source or common-emitter mode, receives the single-ended input signal and generates a first part of the differential output signal. The second transistor, also configured in common-source or common-emitter mode, generates a second part of the differential output signal. The third and fourth transistors are capacitively cross-coupled. The amplifier further comprises inductive degeneration such that a source or emitter of the first transistor is connected to a first inductor and a source or emitter of the second transistor is connected to a second inductor.

Abstract: The power supply unit includes a circuit substrate including a first layer that is a surface layer being conductive, a first wiring pattern formed of the first layer, a second layer that is conductive, and a second wiring pattern formed of the second layer, and first and second capacitors formed on the first layer. The first capacitor includes a first terminal and a second terminal. The second capacitor includes a third terminal and a fourth terminal. The circuit substrate includes a first electrode connecting the first terminal of the first capacitor to the first wiring pattern, a second electrode connecting the second terminal of the first capacitor to the second wiring pattern, a third electrode connecting the third terminal of the second capacitor to the second wiring pattern, and a fourth electrode connecting the fourth terminal of the second capacitor to the first wiring pattern.

Abstract: A primary coil circuit of a ground assembly for wirelessly transferring power to a secondary coil includes: a primary coil magnetically coupled to the secondary coil and having a first terminal and a second terminal; a second capacitor having a first terminal and a second terminal connected to the first terminal of the primary coil; a first inductor having a first terminal coupled to a first input terminal of a power source and a second terminal coupled to the first terminal of the second capacitor; and a first capacitor having a first terminal coupled commonly to the second terminal of the first inductor and the first terminal of the second capacitor and a second terminal coupled commonly to the second terminal of the primary coil and a second input terminal of the power source.

Abstract: In one form, a power amplifier system includes first and second amplification path, and a combination element. The first amplification path has an input for receiving a drive signal, and an output. The second amplification path has an input coupled to the input of the first amplification path, and an output. The second amplification path has a delay element that inserts a signal path delay with respect to the first amplification path, wherein the delay element has a delay corresponding to a harmonic that is desired to be reduced. The combination element is coupled to the output of the first amplification path and an output of the second amplification path, and provides an output signal as a sum of outputs of the first amplification path and the second amplification path.

Abstract: Described herein are systems, architectures, circuits, devices, and methods for a DC-DC converter that dynamically adjusts a supply voltage to a power amplifier based on the number of resource blocks in a signal to be transmitted. The disclosed technologies estimate the number of resource blocks in a signal, generate a signal corresponding to the estimated number of resource blocks, and modify a supply voltage based on the generated signal. The disclosed DC-DC converters can be integrated into systems that employ power management strategies such as average power tracking (“APT”). In addition, the disclosed technologies can be used to improve existing APT-based systems.

Abstract: Exemplary embodiments including an amplifier circuit that includes a radio-frequency (RF) amplifier comprising an input terminal and an output terminal, the RF amplifier being configured to amplify, across a wideband frequency range, an RF signal applied to the input terminal to generate an amplified RF signal at the output terminal. The amplifier circuit also includes a first impedance matching network connected to the RF amplifier output terminal. The first impedance matching network includes a first reactive circuit, having substantially fixed impedance, connected between the RF amplifier input terminal and ground; a second reactive circuit; and a switching device configured to couple the second reactive circuit to the first reactive circuit in an ON state, and to decouple the second reactive circuit from the first reactive circuit in an OFF state. In some embodiments, the amplifier circuit can include a second impedance matching network connected to the RF amplifier input terminal.

Abstract: Provided is a low-noise amplifier that can effectively suppress noise included in an input signal. A low-noise amplifier according to an embodiment of the present invention amplifies a reception signal in a predetermined frequency band from an antenna. The low-noise amplifier includes an input terminal, an output terminal, a field effect transistor, and a branch circuit. The branch circuit is branched from a circuit connecting the input terminal or the output terminal to the field effect transistor. The branch circuit is connected to the elastic wave resonator.

Abstract: Systems, devices and methods related to multi-band power amplifier. In some embodiments, a power amplifier module includes a power amplifier having an output stage and configured to receive a signal. The power amplifier module also includes a first programmable harmonic termination circuit in electrical communication with the output stage of the power amplifier. The first programmable harmonic termination circuit includes a first plurality of capacitors and a first plurality of switches, with at least one of the first plurality of capacitors being in electrical communication with at least one of the first plurality of switches. The power amplifier module further includes a controller configured to modify a configuration of the first plurality of switches of the first programmable harmonic termination circuit based at least in part on a second harmonic frequency of the signal.

Abstract: A power amplification circuit that includes: a capacitor element in which a first metal layer, a first insulating layer, a second metal layer, a second insulating layer and a third metal layer are sequentially stacked, the capacitor element including a first capacitor in which the first metal layer serves as one electrode thereof and the second metal layer serves as another electrode thereof, and a second capacitor in which the second metal layer serves as one electrode thereof and the third metal layer serves as another electrode thereof; and a transistor that amplifies a radio-frequency signal. The radio-frequency signal is supplied to the one electrode of the first capacitor. The other electrode of the first capacitor and the one electrode of the second capacitor are connected to a base of the transistor, and the other electrode of the second capacitor is connected to the emitter of the transistor.

Abstract: Provided are an X-ray detecting apparatus which is capable of controlling an electric power supplied to an X-ray detector module while an X-ray tomography scanning is being performed, and a method for operating the X-ray detecting apparatus. The X-ray detecting apparatus includes an X-ray detector module which has a heat dissipation structure.

Abstract: An energy harvesting system includes a transducer, a capacitor, a power converter, a power converter control line, a control switch and a control switch control line. The transducer harvests energy and outputs electrical current based on the harvested energy. The capacitor stores a rectified voltage based on the electrical current. The control switch can be open or closed. The control switch control line is arranged to provide a control voltage based on the rectified voltage to the control switch. When the control voltage is equal to or greater than a threshold voltage the control switch is closed such that the power converter control line electrically connects the power converter to a battery in order to provide harvested energy to the battery.

Abstract: Systems and methods are provided for band-limited digital pre-distortion (DPD) expansion estimation and curve adjustment. Pre-distortion adjustments may be applied during processing of an input signal, and expansion introduced as result of applying the pre-distortion adjustments may then be estimated. Expansion adjustments may then be determined based on the estimated expansion, and the expansion adjustments may be applied in a feedback manner during subsequent processing operations.

Abstract: A low noise amplifier includes an amplifier transistor having a source, a gate, and a drain. An input node is coupled to the gate. An output node is coupled to the drain. An inductor is coupled between the gate and the drain.

Abstract: An amplifier according to an embodiment of the present invention includes a first transistor and a second transistor that are connected between a ground point and a power supply. A control terminal of the first transistor is connected to an input terminal. A first terminal of the first transistor is connected to the ground point. A second terminal of the second transistor is connected to an output terminal. The amplifier further includes an impedance element and a variable resistance unit. The impedance element is connected between the second terminal of the second transistor and the power supply. The variable resistance unit is connected between the second terminal of the first transistor and the first terminal of the second transistor.

Abstract: A power conversion apparatus includes: DC input terminals for inputting a DC voltage; AC output terminals for outputting an AC voltage; a switching element; a first resonant capacitance connected across the switching element; a first LC resonance circuit that has an inductance and a capacitance connected in series and is connected together with the switching element between the AC output terminals; and a second LC resonance circuit connected in series together with the switching element between the DC input terminals. The second LC resonance circuit includes a first connector portion connected to one DC input terminal and a second connector portion connected to the switching element, and has a first current path, which includes an inductance, and a second current path, which includes a series circuit with an inductance and a capacitance, formed between the first connector portion and the second connector portion.

Abstract: The disclosure provides an amplifier. The amplifier includes a first transistor that receives a first input and generates a first load current. A first output node is coupled to a power supply through a first load resistor. The first load resistor receives the first load current. A first capacitor network is coupled to the first output node and draws a first capacitive current from the first output node. A first current buffer is coupled between the first output node and the first transistor. A current through the first current buffer is a summation of the first load current and the first capacitive current.

Abstract: Radio frequency devices and methods are provided where a network like a filter network or impedance matching network comprises a series connection of at least two inductors.

Abstract: LNA circuitry includes an input node, and output node, a primary amplifier stage, a first ancillary amplifier stage, and an input gain selection switch. The primary amplifier stage is configured to provide a first gain response between a primary amplifier stage input node and a primary amplifier stage output node, wherein the primary amplifier stage input node is coupled to the input node and the primary amplifier stage output node is coupled to the output node. The first ancillary amplifier stage is configured to provide a second gain response between a first ancillary amplifier stage input node and a first ancillary amplifier stage output node, wherein the first ancillary amplifier stage output node is coupled to the primary amplifier stage output node. The input gain selection switch is coupled between the input node and the first ancillary amplifier stage input node.

Abstract: A radio frequency (RF) power transistor circuit includes a power transistor and a decoupling circuit. The power transistor has a control electrode coupled to an input terminal for receiving an RF input signal, a first current electrode for providing an RF output signal at an output terminal, and a second current electrode coupled to a voltage reference. The decoupling circuit includes a first inductive element, a first resistor, and a first capacitor coupled together in series between the first current electrode of the power transistor and the voltage reference. The decoupling circuit is for dampening a resonance at a frequency lower than an RF frequency.

Abstract: A power amplifier module includes an amplifier that amplifies an input signal and outputs an amplified signal, a matching circuit disposed between an output terminal of the amplifier and a subsequent circuit, a choke inductor having a first end to which a power supply voltage is applied and a second end from which power supply is provided to the amplifier through the output terminal of the amplifier, and a first attenuation circuit disposed between the output terminal of the amplifier and the second end of the choke inductor and configured to attenuate a harmonic component of the amplified signal.

Abstract: A device includes a low-noise amplifier (LNA) and a matching circuit. The matching circuit is coupled to an output of the LNA and switchably coupled to at least one of a first and a second output of the device. The device may further include a power splitter switchably coupled between an output of the matching circuit and the first and/or the second output of the device.

Abstract: A power amplifier circuit, including: an input node configured to receive a radio frequency (RF) signal; an output node configured to output an amplified RF signal; a main path switchably coupled between the input node and the output node, and including a first plurality of amplification stages to generate a first amplified RF signal; a bypass path switchably coupled between the input node and the output node, and including at least one second amplification stage to generate a second amplified RF signal; and a coupling switch configured to reuse at least a portion of the bypass path to drive the main path to generate a third amplified RF signal.

Abstract: An impedance-matching circuit includes a resonant circuit, first and second capacitors, and first through third inductive circuits. The resonant circuit includes a fourth inductive circuit connected in parallel with a capacitive circuit. The impedance-matching circuit receives a radio frequency power amplifier (RFPA) output signal, which includes first and second signals at first and second frequencies, respectively. A resonant frequency of the resonant circuit is between the first and second frequencies. The resonant circuit offers inductive and capacitive impedances to the first and second signals, respectively. The impedance-matching circuit generates a matched RFPA output signal including the first signal and the second signal, where the second signal is at a reduced voltage level.

Abstract: A high-frequency module includes a plurality of filters, a switch that commonly connects a plurality of paths, and a low noise amplifier that amplifies a high-frequency signal input from the plurality of filters with the switch interposed therebetween, wherein paths in which first and second filters are respectively provided among the plurality of paths connect the respective filters and the switch without connecting impedance elements, and each of the first and second filters has an output impedance located in a matching region between a NF matching impedance at which an NF of the low noise amplifier is minimum and a gain matching impedance at which a gain of the low noise amplifier is maximum in its respective pass band thereof on a Smith chart.

Abstract: A multi-frequency tunable low-noise amplifier and a multi-frequency tuning implementation method therefor. The amplifier comprises: a system controller (13) and a micro-electro-mechanical system (MEMS) matching tuner (12) connected to the system controller (13). The system controller (13) is configured to respond to a first operation executed by a user via a user interface (15) when in a first mode, to acquire a first matching value produced on the basis of the first operation, and to output the first matching value to the MEMS matching tuner (12). The MEMS matching tuner (12) is configured to be controlled by the system controller (13) and to support the amplifier working on different frequency bands in tuning processing, thus allowing the matching value of the MEMS matching tuner (12) itself to match a current working frequency band.

Abstract: The present disclosure relates to an apparatus, method, system and computer program for amplifying an audio signal derived from an audio signal pickup device, the pickup device having a pickup frequency response profile. The apparatus includes: an amplifier having a maximum open loop frequency response profile in a first frequency range including at least mid-range audible frequencies, the amplifier being configured to apply, in at least the first frequency range, a frequency response profile to the audio signal; wherein the frequency response profile applied to the audio signal is configured such that: it equalises the pickup frequency response profile over the first frequency range, and a difference between a maximum amount of gain able to be applied by the amplifier and an amount of gain applied to the audio signal by the amplifier is substantially constant throughout the first frequency range.

Abstract: An impedance matching circuit be connected to a non-linear impedance including a superconductor, includes a first terminal designated first connection port to be connected to a first connector of the non-linear impedance, a second terminal designated second connection port to be connected to a second connector of the non-linear impedance, a third terminal designated input/output terminal to receive the signal to amplify and a fourth terminal designated supply terminal to be connected to a polarisation source and configured so that a voltage V is applied between the first connection port and the second connection port. The circuit further includes a plurality of passive electrical components.

Abstract: A circuit includes an amplifier configured to amplify an input signal and generate an output signal. The circuit also includes a tuning network configured to tune frequency response of the amplifier. The tuning network includes at least one tunable capacitor, where the at least one tunable capacitor includes at least one micro-electro mechanical system (MEMS) capacitor. The amplifier could include a first die, the at least one MEMS capacitor could include a second die, and the first die and the second die could be integrated in a single package. The at least one MEMS capacitor could include a MEMS superstructure disposed over a control structure, where the control structure is configured to control the MEMS superstructure and tune the capacitance of the at least one MEMS capacitor.

Abstract: A rectenna includes (a) a multi-band multi-channel (MBMC) matching network, and/or (b) an adaptively reconfigurable rectifier or a breakdown-protected rectifier. An MBMC matching network includes a plurality of T-shaped transmission line matching structures coupled in series. An adaptively reconfigurable rectifier circuit includes a low input power rectifying portion, a high input power rectifying portion, and a set of transistors configured for selectively and automatically transitioning the adaptively reconfigurable rectifier between a low input power operating configuration and a high input RF power operating configuration, in a manner correlated with input RF power level. A breakdown-protected rectifier includes a transistor-protected diode structure having a diode coupled to a transistor in a manner that protects the diode from direct exposure to negative voltages that would ordinarily cause the diode to break down in the absence of the transistor.

Abstract: A method for redeeming a coupon using a mobile device is disclosed. The method comprises allowing a user to select the coupon; accessing at least one melody stored in a memory of the mobile device; passing a coupon identifier for the coupon and the at least one melody to an encoder component of the mobile device encoding the coupon identifier and the melody by the encoder component to generate a signal for transmission; and transmitting said signal through a speaker of said mobile device for reception through a microphone of a receiving mobile device.

Abstract: Embodiments of the present invention provide a LCD Q-Panel, a LCD panel and a LCD apparatus, for solving the technical problem that there is a large loss of a signal over the resistance of the signal transmission line when the signal is loaded into a general signal connection port of the LCD Q-Panel in the prior art. The LCD Q-Panel provided in embodiments of the present invention comprises: a general signal connection port, at least one LCD panel comprising a signal connection point, and at least one voltage follower; the signal input from the general signal connection port is transmitted via the at least one voltage follower to the signal connection point connected to an output terminal of the at least one voltage follower and the LCD panel comprising the signal connection point.

Abstract: Systems and methods for providing wireless communication impairment correction using non-linear iterative precoding by a transmitter device are disclosed. The transmitter may exploit the non-linear transmit indications, and perform digital non-linear multiple input multiple output (MIMO) precoding of a transmit signal to improve the error vector magnitude (EVM) at the intended receiver device and/or reduce the adjacent channel leakage ratio (ACLR) at the unintended receiver devices. The non-linear transmit indications may comprise amplitude modulation to amplitude modulation (AM-AM) and amplitude modulation to phase modulation (AM-PM) indications. In operation, the non-linear transmit indications may be received from the intended receiver devices or may be measured by the transmitter device.

Abstract: The application relates to a spreading signal generating method, generating device, receiving method and receiving device. The spreading signal generating method comprises: generating a first spreading signal component and a second spreading signal component, wherein the first spreading signal component and the second spreading signal component each comprise a spreading code and a binary subcarrier, the spreading code of the first spreading signal component is the same as the spreading code of the second spreading signal component, the binary subcarrier of the first spreading signal component is different from the binary subcarrier of the second spreading signal component; and modulating the first spreading signal component and the second spreading signal component with radio frequency (RF) carriers so as to generate the spreading signal, where a phase of RF carrier for modulating the first spreading signal component is different from a phase of RF carrier for modulating the second spreading signal component.

Abstract: A power amplification module includes: an amplifier that amplifies an input signal and outputs an amplified signal; and a harmonic-termination circuit to which harmonics of the amplified signal are input and the impedance of which is controlled in accordance with the frequency of a harmonic. The power amplification module can operate in a first mode in which a power supply voltage changes in accordance with the average voltage value of the amplified signal over a prescribed time period or in a second mode in which the power supply voltage changes in accordance with the envelope of the input signal. The impedance of the harmonic-termination circuit is controlled such that at least one even-ordered harmonic is short-circuited when the power amplification module operates in the first mode and at least one odd-ordered harmonic of third order or higher is short-circuited when the power amplification module operates in the second mode.

Abstract: Matching network for broadband power amplifier. In some embodiments, a power amplifier can include an amplifying transistor having an input and an output, and a matching circuit coupled to the output of the amplifying transistor. The matching circuit can include a first capacitance, an inductance, and a second capacitance connected in series. The matching circuit can further include a third capacitance implemented in a shunt path from a node between the first capacitance and the inductance to a ground, and a fourth capacitance implemented in a shunt path from a node between the inductance and the second capacitance to the ground.

Abstract: Apparatuses including compensation capacitors are described. An example apparatus includes: first, second and third capacitors arranged such that the second capacitor is sandwiched between the first and third capacitors, each of the first, second and third capacitors including first and second electrodes. The first electrodes of the first, second and third capacitors are electrically coupled in common to one another. The second electrodes of the first and third capacitors are electrically coupled in common to each other. The second electrode of the second capacitor is electrically insulated from the second electrodes of the first and third capacitors.

Abstract: An RF amplifier includes a transistor, a shunt circuit, an envelope frequency termination circuit, and an extra lead. The shunt circuit is coupled between a transistor current carrying terminal and a ground reference node. The shunt circuit has a shunt inductive element and a shunt capacitor coupled in series, with an RF cold point node between the shunt inductive element and the shunt capacitor. The envelope frequency termination circuit is coupled between the RF cold point node and the ground reference node. The envelope frequency termination circuit has an envelope resistor, an envelope inductive element, and an envelope capacitor coupled in series. The extra lead is electrically coupled to the RF cold point node. The extra lead provides a lead inductance in parallel with an envelope inductance provided by the envelope inductive element. An additional shunt capacitor can be coupled between the extra lead and ground.

Abstract: A transmission module includes an amplifier that amplifies a plurality of transmission signals in different frequency bands, a power supply voltage regulator circuit that supplies different power supply voltages for the respective frequency bands of the transmission signals to the amplifier, and a variable matching circuit including at least one variable capacitor element and at least one fixed inductor element. The variable matching circuit satisfies different output impedance matching conditions of the amplifier for the respective frequency bands of the transmission signals by changing a capacitance value of the at least one variable capacitor element on the basis of a change in the output impedance matching conditions of the amplifier in response to a change in the power supply voltages supplied to the amplifier.

Abstract: A transmission circuit includes a transmission signal generation unit, a control unit, and a transmission signal amplification unit. The transmission signal generation unit generates a transmission signal that has been modulated. The transmission signal amplification unit includes a power amplifier that amplifies the transmission signal. The control unit determines a supply voltage signal having an amplitude characteristic of a period identical to that of an envelope of the transmission signal and supplies the supply voltage signal to the power amplifier. The control unit determines an output timing of the supply voltage signal such that a phase difference between a phase of the envelope of the transmission signal and a phase of the supply voltage signal does not become zero.