Abstract: A Doherty amplifier includes a peaking amplifier, a carrier amplifier, and a combining node electrically connected to the carrier amplifier and the peaking amplifier. The Doherty amplifier includes a harmonic control circuit coupled to the combining node. The harmonic control circuit includes an inductor and a capacitor and the inductor and capacitor are connected in series between the first current conducting terminal and a ground reference node. An inductance value of the inductor of the harmonic control circuit and a capacitance value of the capacitor of the harmonic control circuit are selected to terminate second order harmonic components of a fundamental frequency of a signal generated by the carrier amplifier.

Abstract: Examples disclosed herein relate to a Doherty Power Amplifier (“DPA”) with integrated second harmonic injection. The DPA includes an amplifier circuit having a carrier amplifier and a peaking amplifier, and a combiner network coupled to the amplifier circuit, the combiner network having a plurality of transmission lines and a LC resonant circuit to inject a second harmonic from the carrier amplifier into the peaking amplifier.

Abstract: A barely Doherty dual envelope tracking (BD2E) circuit has a transmitter chain that includes an envelope tracking (ET) circuit that controls a Doherty dual power amplifier array. The ET circuit provides two control signals (supply voltage signals) that are used to control or modulate a carrier amplifier and a peaking amplifier independently of one another. The BD2E circuit includes an improved impedance inverter that isolates the peaking amplifier from the carrier amplifier to allow this independent control. By providing independent control, greater linearity may be provided while preserving the efficiency of the circuit.

Abstract: A power amplifier device includes a semiconductor substrate; a plurality of first transistors that are provided on the semiconductor substrate and receive input of a radio-frequency signal; a plurality of second transistors that are provided on the semiconductor substrate and electrically connected to the respective plurality of first transistors, and output a radio-frequency output signal obtained by amplifying the radio-frequency signal; a plurality of first bumps provided so as to overlay the respective plurality of first transistors; and a second bump provided away from the plurality of first bumps and provided so as not to overlay the plurality of first transistors and the plurality of second transistors. When viewed in plan from a direction perpendicular to a surface of the semiconductor substrate, a first transistor and a first bump, a second transistor, the second bump, a second transistor, and a first transistor and a first bump are arranged in sequence.

Abstract: A dual amplifier apparatus is disclosed. The apparatus includes an energy module having a controller and a first and second power amplifier circuit coupled to the controller. The first and second power amplifier circuits are configured to receive and amplify an input signal to generate a first output signal into a load coupled to the output of the first and second power amplifier circuit. A power rating of the first amplifier circuit is different from a power rating of the second amplifier circuit. The controller is configured to select the first or the second power amplifier circuit.

Abstract: Example embodiments relate to power amplifiers with decreased RF return current losses. One embodiment includes a RF power amplifier package that includes a semiconductor die, an input lead, first bondwire connections, second bondwire connections, and a plurality of shields. The semiconductor die includes an RF power transistor that includes output bond pads, input bond pads, a plurality of input fingers, and a plurality of output fingers. Further, each shield of the plurality of shields is arranged in between a respective input finger of the plurality of input fingers and a respective output finger of the plurality of output fingers and extending along with said respective input finger and output finger. In addition, each shield of the plurality of shields is connected to a ground terminal of the RF power transistor. The input fingers, output fingers, and shields are formed using a metal layer stack of multiple metal layers.

Abstract: Apparatus and methods for an inverted Doherty amplifier operating at gigahertz frequencies are described. RF fractional bandwidth and signal bandwidth may be increased over a conventional Doherty amplifier configuration when impedance-matching components and an impedance inverter in an output network of the inverted Doherty amplifier are designed based on characteristics of the main and peaking amplifier and asymmetry factor of the amplifier.

Abstract: A high frequency amplifier includes an asymmetrical Doherty amplifier having a carrier amplifier, a peak amplifier, a branch circuit, and a phase adjusting circuit, a driver amplifier, and a base member mounting a first circuit board mounting the driver amplifier, the carrier amplifier, and the peak amplifier and a second circuit board mounting the circuits. The branch circuit divides a path of a RF signal into input paths of the peak and carrier amplifiers. The driver amplifier, the carrier amplifier, and the peak amplifier have rear surfaces in contact with the base member. The electrical length from the output terminal of the driver amplifier to the input terminal of the peak amplifier, when converted based on a phase of the signal, is from (2n+1)×???/4 to (2n+1)×?+?/4, where n is an integer greater than or equal to zero.

Abstract: Low-load-modulation, broadband power amplifiers and method of use are described. The amplifiers can include multiple amplifiers connected in parallel to amplify a signal that has been divided into parallel circuit branches. One of the amplifiers can operate as a main amplifier in a first amplification class and the remaining amplifiers can operate as peaking amplifiers in a second amplification class. The main amplifier can see low modulation of its load between the fully-on and fully backed-off states of the amplifier. With lower load modulation, the power amplifiers described herein exhibit better power-handling capability and RF fractional bandwidth as compared to conventional amplifiers.

Abstract: An LNA having a plurality of paths, each of which can be controlled independently to achieve a gain mode. Each path includes at least an input FET and an output FET coupled in series. A gate of the output FET is controlled to set the gain of the LNA. Signals to be amplified are applied to the gate of the input FET. Additional stacked FETs are provided in series between the input FET and the output FET.

Abstract: The present invention relates to a high-frequency semiconductor device. A conventional high-frequency semiconductor device including an input second-order harmonic matching circuit has such a problem that gain decrease occurs. In a high-frequency semiconductor device (100) of the present invention, two adjacent unit transistor cells (7) and (8) are connected to one input second-order harmonic matching circuit (19) provided on an upper surface of a semiconductor substrate (1). The input second-order harmonic matching circuit (19) includes a first capacitor (13), a first inductor (14), a second capacitor (15), and a second inductor (16). The first capacitor (13) and the first inductor (14) resonate at the frequency of a fundamental wave, and each of impedances as seen by input electrodes of the two unit transistor cells (7) and (8) is short-circuited at the frequency of a second-order harmonic.

Abstract: A Doherty amplifier includes a divider configured to divide input power into first input power and second input power, and a carrier amplifier configured to amplify the first input power. The Doherty amplifier includes an adaptive attenuator configured to attenuate the second input power, the adaptive attenuator being configured to increase an attenuation amount upon detecting that the second input power is less than a predetermined value. The Doherty amplifier includes a peaking amplifier configured to amplify the attenuated second input power, and a combiner configured to combine output power of the carrier amplifier with output power of the peaking amplifier.

Abstract: A semiconductor device and an amplifier assembly implementing the semiconductor device are disclosed. The semiconductor device, which is a type of Doherty amplifier, includes first transistor elements for a carrier amplifier of the Doherty amplifier and second transistor elements for a peak amplifier. A feature of the Doherty amplifier is that the first transistor elements and the second transistor elements are disposed alternatively on a common semiconductor substrate.

Abstract: Apparatus and methods for a modified Doherty amplifier operating at gigahertz frequencies are described. The combining of signals from a main amplifier and a peaking amplifier occur prior to impedance matching of the amplifier's output to a load. An output impedance-matching element can be relied upon. In one example, the output impedance-matching element can include an output strip line, a shunt capacitor connected between the output strip line and ground, an output capacitor connected between the output strip line and an output bonding pad, and an inductive strip line connected between the output bonding pad and ground.

Abstract: Apparatus and methods for a low-load-modulation power amplifier are described. Low-load-modulation power amplifiers can include multiple amplifiers connected in parallel to amplify a signal that has been divided into parallel circuit branches. One of the amplifiers can operate as a main amplifier in a first amplification class and the remaining amplifiers can operate as peaking amplifiers in a second amplification class. The main amplifier can see low modulation of its load between the power amplifier's fully-on and fully backed-off states. Improvements in bandwidth and drain efficiency over conventional Doherty amplifiers are obtained.

Abstract: A polar transmitter is provided. The polar transmitter includes a baseband generation unit configured to generate phase data bits and amplitude data bits of an output pulse. The polar transmitter further includes a bandwidth control unit downstream to the baseband generation unit configured to regulate the width of the output pulse. Moreover, the polar transmitter includes a pulse shaping unit downstream to the bandwidth control unit configured to generate a predefined amplitude envelope of the output pulse. In this context, the pulse shaping unit includes a delay-line with a plurality of taps, where each tap output is configured to be amplitude weighted in order to generate the amplitude envelope of the output pulse.

Abstract: A circuit includes a transformer having a primary coil coupled to a first power amplifier (PA) and a second PA, and a secondary coil. The secondary coil supplies a current to an antenna based on a first direction of a first phase of a first amplified constant-envelope signal in the primary coil with respect to a second phase of a second amplified constant-envelope signal in the primary coil. The circuit further includes load impedance coupled between a median point of the primary coil and ground. The load impedance is adjusted to match one of an impedance of the differential antenna, an impedance of the first PA, and an impedance of the second PA, based on the ripples detected by the ripple detector.

Abstract: Various methods and circuital arrangements for biasing one or more gates of stacked transistors of an amplifier are possible where the amplifier is configured to operate in at least an active mode and a standby mode. Circuital arrangements can reduce bias circuit standby current during operation in the standby mode while allowing a quick recovery to normal operating conditions of the amplifier. Biasing an input transistor of the stacked transistors can be obtained by using a replica stack circuit.

Abstract: Provided herein are apparatus and methods for a multi-stage signal-processing circuit. The signal-processing circuit can include multiple configurable stages that can be cascaded and configured to process an input signal. Control circuitry can be used to select an output of the configurable stages. Serial data can be recovered with good signal integrity using a signal monitor with the configurable stages by virtually placing the signal monitor on a buffered output node.

Abstract: A high-efficiency amplifier is configured so that short stubs are provided in a line between a first substrate end and a second substrate end of a substrate, and among the short stubs, short stubs provided at locations other than both ends of the line include two short stubs and which are adjacent to each other, and which are provided at locations at which the two short stubs are to be electromagnetically coupled to each other.

Abstract: An amplifier device includes a substrate, a composite packaged amplifier having a bottom plate and an output plate, a first amplifier and a second amplifier provided on the bottom plate, a combining node that combines an output of the first amplifier with an output of the second amplifier, an output matching circuits provided on the bottom plate, that has a first transmission line provided between the first amplifier and the combining node, and a second transmission line provided between the combining node and the second amplifier, a third transmission line having one transmission line on which the output plate is mounted and other transmission line that connects the one transmission line to the external port, and wirings connecting to one terminal of the output plate and the combining node. A length of the output plate and the other transmission line is equal or less than ?/4 radian for a signal.

Abstract: An amplifier includes an input matching network; at least one transistor; an input lead coupled to the at least one transistor; a ground terminal coupled to the transistor; an output lead coupled to the at least one transistor; an output matching circuit coupled to the output lead and to the at least one transistor; and a baseband impedance enhancement circuit having at least one reactive element coupled to the input matching network. The baseband impedance enhancement circuit is configured to reduce resonances of a baseband termination.

Abstract: The present disclosure relates to added isolation between transistors in a multiple path amplifier circuit. The multiple path amplifier circuit includes a substrate, a first transistor on the substrate in a first path, and a second transistor on the substrate in a second path. The multiple path amplifier circuit also includes at least one electrical connection associated with the first and the second transistors and positioned to at least partially extend between the first path and the second path.

Abstract: Provided are an input matching circuit, at least one amplifying transistor that receives a signal from the input matching circuit, a first dummy transistor that receives a signal from the input matching circuit, a second dummy transistor that receives a signal from the input matching circuit, and an output matching circuit that outputs an output of the amplifying transistor, the amplifying transistor being arranged between the first dummy transistor and the second dummy transistor, the amplifying transistor, the first dummy transistor, and the second dummy transistor being provided in a row along the input matching circuit.

Abstract: A digital transmitter architecture is disclosed to transmit (TX) multi-gigabit per second data signals on single carriers (SC) or orthogonal frequency division multiplexing (OFDM) carriers at millimeter wave frequencies in either one of a high-resolution modulation mode or a spectral shaping mode. The architecture includes a number of digital power amplifier (DPA) and modulation reconfigurable circuit segments to process individual bits of a data bit stream in parallel according to a specific circuit configuration corresponding to the selected TX mode using a multiplexer to switch between configurations.

Abstract: An amplifier includes a transistor, an input circuit coupled between an amplifier input and a transistor input terminal, and an output circuit coupled between a transistor output and a transistor output terminal. The input circuit includes an input-side harmonic termination circuit with a first inductor and a first capacitance in series between the transistor input terminal and ground. The output circuit includes a second inductor, an output-side harmonic termination circuit, and a shunt-L circuit. The second inductor is coupled between the transistor output terminal and the amplifier output. The output-side harmonic termination circuit includes a third inductor and a second capacitance in series between the amplifier output and ground. The shunt-L circuit includes a fourth inductor and a third capacitance connected in series between the amplifier output and ground.

Abstract: Exemplary aspects are directed to a power-amplification circuit including multiple in-parallel circuit paths, each including a power amplifier driving an immittance converter. Current from each output of the respective immittance converters is combined for delivery to a load. In a more specific example, a control circuit may be used to modulate, such as by enabling or disabling power delivered from, one or more of the power amplifiers for fast, coarse resetting of the overall power delivered to the load, and/or to modulate one or more of the modulate immittance converters (e.g., via a phase or signal-timing adjustment) to finely tune the resetting of the overall power delivered to the load. Using the control circuit for providing both the coarse adjustment and the fine adjustment, and fast acting precise delivery of overall power delivered to a load may be realized for any of a variety of applications.

Abstract: A radio frequency amplifier circuit is provided. A matching circuit is configured on a radio frequency path of an input end or an output end of an amplifier. An inductance-capacitance resonance circuit and the matching circuit share an inductor included in the matching circuit to generate a corresponding resonance frequency. The matching circuit provides an input impedance or an output impedance matching two fundamental tones in a radio frequency signal at a first frequency and a second frequency. The inductance-capacitance resonance circuit provides a filtering path for filtering a signal component outside a frequency band formed by the first frequency and the second frequency in the radio frequency signal.

Abstract: Spatial power-combining devices with reduced dimensions are disclosed. Spatial power-combining devices are provided that employ a hybrid structure including both a planar splitter/combiner and an antipodal antenna array. Planar splitters may be arranged to divide an input signal while antipodal antenna arrays may be arranged to combine amplified signals. In other applications, the order may be reversed such that antipodal antenna arrays are arranged to divide an input signal while a planar combiner is arranged to combine amplified signals. Advantages of such spatial power-combining devices include reduced size and weight while maintaining suitable performance for operation in desired frequency bands.

Abstract: In each E-class inverter, an internal voltage detection circuit detects an internal voltage of a resonant type power supply circuit or a matching circuit and adjusts a phase of a driving signal of a MOSFET based on a detected voltage. It is thus possible to match a phase of a current voltage of a sine waveform of each inverter and combine power highly efficiently. Since power combining is performed highly efficiently without using a variable capacitor and variable inductor, it is possible to suppress upsizing of elements and achieve downsizing of a power amplifier circuit.

Abstract: A package (1) includes first and second input terminals (2,3) which are adjacent to each other, and first and second output terminals (4,5) which are adjacent to each other. A first input matching circuit (6), a first delay circuit (7), a second input matching circuit (8), a first amplifier (9), and a first output matching circuit (10) are sequentially connected between the first input terminal (2) and the first output terminal (4) inside the package (1). A third input matching circuit (11), a second amplifier (12), a second output matching circuit (13), a second delay circuit (14), and a third output matching circuit (15) are sequentially connected between the second input terminal (3) and the second output terminal (5) inside the package (1). First to fourth matching circuits (16-19) are respectively connected to the first input terminal (2), the second input terminal (3), the first output terminal (4) and the second output terminal (5) outside the package (1).

Abstract: A balanced-to-Doherty (B2D) mode-reconfigurable power amplifier (PA) has the capability of maintaining high linearity and high efficiency against load mismatch. The reconfigurable PA includes a switch to alternatively connect to a pre-determined resistive load or a pre-determined pure reactive load (jX), i.e., short, open, or finite reactance between an output quadrature coupler and ground. The biasing of Doherty mode is adaptive dependent on the value of reactive loading (jX). The Doherty operation of this PA is based on an architecture configured from a balanced amplifier, e.g., a quasi-balanced amplifier.

Abstract: The present disclosure relates to a 5th generation (5G) or pre-5G communication system for supporting a data transmission rate higher than that of a 4th generation (4G) communication system such as long term evolution (LTE). The present disclosure is to amplify transmission signals in a wireless communication system, and a transmitting device may include an antenna array including a plurality of antenna elements, a plurality of amplification chains for amplifying signals transmitted through the plurality of the antenna elements, and a power supply line for supplying powers to the plurality of the amplification chains. Herein, the powers used by power amplifiers included in at least one amplification chain of the plurality of the amplification chains may be divided by filtering or by independent pads and branch-lines.

Abstract: A Doherty amplifier includes: a transistor for a carrier amplifier; a transistor for a peak amplifier; a transmission line connected between an output terminal of the transistor for the carrier amplifier and an output terminal of the transistor for the peak amplifier; a stub that is connected in parallel to the output terminal of the transistor for the peak amplifier and that is capacitive and inductive in a working frequency band; and an output matching circuit connected to the output terminal of the transistor for the peak amplifier, the transmission line, and an output load, the output matching circuit to transform an impedance of the output load into an impedance lower than the impedance of the output load.

Abstract: A power amplifier circuit includes a first path and a second path between an input terminal and an output terminal, a first amplifier located in the first path operative in a first mode, a second amplifier located in the second path operative in a second mode, a first matching circuit between the first amplifier and the output terminal in the first path, a first capacitor having a first end connected to the output terminal side of the first matching circuit, and a second end, a first inductor having a first end connected to the second end of the first capacitor and a second end grounded, and a short-circuit switch connected in parallel with the first inductor. The short-circuit switch short-circuits the first and second ends of the first inductor in the first mode and is placed in an open-circuit position in the second mode.

Abstract: A power amplifier includes a power splitter that splits a first signal into a second signal and a third signal, a first amplifier that amplifies the second signal within an area where the first signal has a power level greater than or equal to a first level and that outputs a fourth signal, a second amplifier that amplifies the third signal within an area where the first signal has a power level greater than or equal to a second level higher than the first level and that outputs a fifth signal, an output unit that outputs an amplified signal of the first signal, a first and a second LC parallel resonant circuit, and a choke inductor having an end to which a power supply voltage is supplied and another end connected to a node of the first and second LC parallel resonant circuits.

Abstract: A method for making a wideband Doherty amplifier with reduced plan width, adapted to transport a radio-frequency signal at a frequency value comprised within a frequency range defined between a minimum frequency value and a maximum frequency value, the amplifier including: a signal source adapted to generate an input signal; a hybrid coupler or a splitter network adapted to receive the input signal and divide it into first and second output signals phase-shifted by 90°; a carrier amplifier adapted to receive as input the first output signal; a peak amplifier adapted to receive as input the second output signal; an output network arranged between the carrier and peak amplifiers and a delivery node adapted to be connected to a load, the output network including a recombination node adapted to receive the signals output by the carrier amplifier and the peak amplifier, and a transmission line implemented as a printed circuit track applied to an insulating substrate, wherein capacitors are inserted on the track wh

Abstract: A method and transmitter for a Doherty power amplifier are provided. According to one aspect, a radio transmitter includes, for each carrier frequency, a filter, a main path and a peak path. The filter suppresses signals outside the selected frequency band to produce a filter output. The main path is configured to make a first adjustment of a magnitude and phase of the filter output to produce a main path signal. The peak path is configured to make a second adjustment of the magnitude and phase of the filter output to produce a peak path signal, a difference between the first adjustment and the second adjustment being dependent on the carrier frequency. Main path signals for each carrier frequency produce a composite main path signal. Peak path signals for each carrier frequency produce a composite peak path signal.

Abstract: A multiple-path amplifier (e.g., a Doherty amplifier) includes a semiconductor die, a radio frequency (RF) signal input terminal, a combining node structure integrally formed with the semiconductor die, and first and second amplifiers (e.g., main and peaking amplifiers) integrally formed with the die. Inputs of the first and second amplifiers are electrically coupled to the RF signal input terminal. A plurality of wirebonds is connected between an output of the first amplifier and the combining node structure. An output of the second amplifier is electrically coupled to the combining node structure (e.g., through a conductive path with a negligible phase delay). A phase delay between the outputs of the first and second amplifiers is substantially equal to 90 degrees. The second amplifier may be divided into two amplifier portions that are physically located on opposite sides of the first amplifier.

Abstract: A Doherty power amplifier comprises a splitter network, a first amplifier path comprising at least a first sub-amplifier and a first output matching network; and a second amplifier path comprising at least a second sub-amplifier amplifier and a second output matching network. The Doherty power amplifier further comprises a load modulation network comprising four transmission lines. Each transmission line is a quarter wavelength line at a fundamental frequency of the input signal.

Abstract: A radio frequency module is provided. A matching circuit includes an inductor which is connected in series to the power amplifier and is formed in a substrate. The substrate includes a ground layer, a low permittivity portion, and a high permittivity portion. The ground layer at least partially overlaps with a first input terminal of the low-noise amplifier in a plan view from a thickness direction of the substrate. The low permittivity portion at least partially overlaps with the first input terminal in a plan view from the thickness direction, and is provided between the first input terminal and the ground layer. The high permittivity portion is in contact with the inductor and has the permittivity greater than the permittivity of the low permittivity portion.

Abstract: The present invention relates to an amplifying device and to an amplifying system comprising the same. According to the present invention, an amplifier line-up is presented comprising four amplifying units which is operable in a Doherty mode and an outphasing mode. By integration of Chireix compensating elements in the matching networks used in the amplifying units a bandwidth improvement can be obtained.

Abstract: The exemplified disclosure presents a highly power efficient amplifier (e.g., front-end inverter and/or amplifier) that achieves significant current reuse (e.g., 6-time for a 3-stack embodiments) by stacking inverters and splitting the capacitor feedback network. In some embodiments, the exemplified technology facilitates N-time current reuse to substantially reduced power consumption. It is observed that the exemplified disclosure facilitates significant current-reuse operation that significantly boost gain gm while providing low noise performance without increasing power usage. In addition, the exemplified technology is implemented such that current reuse and number of transistor has a generally linear relationship and using fewer transistors as compared to known circuits of similar topology.

Abstract: A multiple-path (e.g., Doherty) amplifier includes a semiconductor die, a radio frequency (RF) signal input terminal, a combining node structure integrally formed with the semiconductor die, first and second amplifiers (e.g., main and peaking amplifiers, or vice versa) integrally formed with the semiconductor die, and a shunt circuit electrically connected between an output of the first amplifier and a ground reference node. Inputs of the first and second amplifier are electrically coupled to the RF signal input terminal, and outputs of the first and second amplifier are electrically coupled to the combining node structure. The shunt circuit includes a shunt inductance and a shunt capacitance coupled in series between the output of the first amplifier and the ground reference node, and the shunt capacitance has a first terminal coupled to the shunt inductance, and a second terminal coupled to the ground reference node.

Abstract: An embodiment of this disclosure provides an automated payment apparatus. The apparatus includes a photodiode current integrator configured to charge an integration capacitor. The photodiode current integrator includes a first feedback resistor connected along a negative feedback path of an operational amplifier between an output of the operational amplifier and a negative input of the operational amplifier. The photodiode current integrator also includes a second feedback resistor connected along a positive feedback path of the operational amplifier between the output of the operational amplifier and a positive input of the operational amplifier. The photodiode current integrator also includes an integration capacitor connected to the positive input of the operational amplifier and to common circuit ground. The photodiode current integrator also includes a reset switch connected to the positive input of the operational amplifier and to common circuit ground or to additional voltage source.

Abstract: A Doherty amplifier system is disclosed with a carrier amplifier configured to amplify a first portion of a radio frequency (RF) signal. A peaking amplifier with a peaking output is configured to amplify a second portion of the RF signal when it is above a power level threshold. A first inductor is coupled between the main output and a first middle node, and a second inductor is coupled between the first middle node and the peaking output. The first inductor and the second inductor are configured to have a first magnetic coupling to form a first impedance inverter. A third inductor is coupled between the peaking output and a second middle node, and a fourth inductor is coupled between the second middle node and an RF signal output. The third inductor and the fourth inductor are configured to have a second magnetic coupling to form a second impedance inverter.

Abstract: A Doherty amplifier circuit having a tunable impedance and phase (“TIP”) circuit to provide an adjustable alpha factor, which allows for a selection of power added efficiency (PAE) curves that are useful for applications having different modulations or to meet other criteria. Embodiments include a Doherty amplifier having a TIP circuit that provides for tunability of the impedance ZINV (resulting in an adjustable alpha factor) while maintaining the phase of the output of the carrier amplifier at 90° (for a selected polarity)±a low phase variation. Embodiments of the TIP circuit include one or more series-connected TIP cells comprising at least one TIP circuit combined with a tunable phase adjustment circuit. In operation, when the impedance of a TIP cell is adjusted, adjustments within the cell are also made to provide a phase shift correction back towards 90° (at the selected polarity).

Abstract: An apparatus and method for electrical power splitting with a reduced physical size by using reactive electrical components, producing an increase in signal isolation among output ports and a reduction in internal electrical losses, and operable over a large bandwidth extending from DC to microwave frequencies. Attenuators with capacitors in parallel are used inboard of each output port to achieve extended broadband operation. 2-way and N-way power splitters and corresponding power combiners are described.

Abstract: A transformer-based Doherty power amplifier includes a main power amplifier path and an auxiliary power amplifier path which are connected in parallel. The main power amplifier path includes a main power amplifier, and the auxiliary power amplifier path includes an auxiliary power amplifier. The transformer-based Doherty power amplifier further includes a first linear network circuit or a second linear network circuit. The first linear network circuit is arranged at an input of the main power amplifier and is used to compensate for variations of an input capacitance of the main power amplifier, so as to improve the linearity of the main power amplifier. The second linear network circuit is arranged at an input of the auxiliary power amplifier and is used to compensate for variations of an input capacitance of the auxiliary power amplifier, so as to improve the linearity of the auxiliary power amplifier.

Abstract: Apparatus and methods for an inverted Doherty amplifier operating at gigahertz frequencies are described. RF fractional bandwidth and signal bandwidth may be increased over a conventional Doherty amplifier configuration when impedance-matching components and an impedance inverter in an output network of the inverted Doherty amplifier are designed based on characteristics of the main and peaking amplifier and asymmetry factor of the amplifier.