An outphasing amplifier includes a first class-E power amplifier having an output coupled to a first conductor and an input receiving a first RF drive signal. A first reactive element is coupled between the first conductor and a second conductor. A second reactive element is coupled between the second conductor and a third conductor. A second class-E power amplifier includes an output coupled to a fourth conductor and an input coupled to a second RF drive signal, a third reactive element coupled between the second and fourth conductors. Outputs of the first and second power amplifiers are combined by the first, second and third reactive elements to produce an output current in a load. An efficiency enhancement circuit is coupled between the first and fourth conductors to improve power efficiency at back-off power levels. Power enhancement circuits are coupled to the first and fourth conductors, respectively.

A power amplifier module includes a first substrate and a second substrate, at least part of the second substrate being disposed in a region overlapping the first substrate. The second substrate includes a first amplifier circuit and a second amplifier circuit. The first substrate includes a first transformer including a primary winding having a first end and a second end and a secondary winding having a first end and a second end; a second transformer including a primary winding having a first end and a second end and a secondary winding having a first end and a second end; and multiple first conductors disposed in a row between the first transformer and the second transformer, each of the multiple first conductors extending from the wiring layer on a first main surface to the wiring layer on a second main surface of the substrate.

Wideband power combiners and splitters are provided herein. In certain embodiments, a power combiner/splitter is implemented with a first coil connecting a first port and a second port, and a second coil connecting a third port and a fourth port. The first coil and the second coil are inductively coupled to one another. For example, the first coil and the second coil can be formed using adjacent conductive layers of a semiconductor chip, an integrated passive device, or a laminate. The power combiner/splitter further includes a fifth port tapping a center of the first coil and a sixth port tapping a center of the second coil. The fifth port and the sixth port serve to connect capacitors and/or other impedance to the center of the coils to thereby provide wideband operation.

An apparatus for detecting difference in operating characteristics of a main circuit by using a replica circuit is presented. In one exemplary case, a sensed difference in operating characteristics of the two circuits is used to drive a tuning control loop to minimize the sensed difference. In another exemplary case, several replica circuits of the main circuit are used, where each is isolated from one or more operating variables that affect the operating characteristic of the main circuit. Each replica circuit can be used for sensing a different operating characteristic, or, two replica circuits can be combined to sense a same operating characteristic.

An embodiment of a dual-path amplifier includes a power splitter connected to first and second power amplifiers respectively connected to first and second transmission lines connected to a power combiner having a phase-offset deficit at the second harmonic frequency 2f0, where the first and second transmission lines are designed to provide a complementary phase offset at 2f0 substantially equal to the phase-offset deficit such that the two amplified signals will be combined at the power converter with a total phase offset at 2f0 of about 180 degrees in order to reduce harmonic distortion in the amplified output signal, without substantially diminishing the output power at the fundamental frequency f0. In certain PCB-based implementations, the transmission lines include metal traces and lumped elements providing different impedance transformations that achieve the complementary phase offset, where the metal traces may have significantly different physical and electrical characteristics.

Apparatus and methods for quadrature combined Doherty amplifiers are provided herein. In certain embodiments, a separator is used to separate a radio frequency (RF) input signal into a plurality of input signal components that are amplified by a pair of Doherty amplifiers operating in quadrature. Additionally, a combiner is used to combine a plurality of output signal components generated by the pair of Doherty amplifiers, thereby generating an RF output signal exhibiting quadrature balancing.

An amplifier (300) comprising: a first signal path comprising first amplifier circuitry (105A) configured to receive a first signal (RF1) with a frequency and a variable phase and amplitude at the frequency; a second signal path comprising second amplifier circuitry (105B) configured to receive a second signal (RF2) with the frequency, wherein at least one of the relative phase and amplitude of the second signal is fixed at the frequency; combiner circuitry (106) configured to combine an output of the first amplifier circuitry and the second amplifier circuitry.

Various aspects of integrated amplifiers, layouts for the integrated amplifiers, and packaged arrangements of the amplifiers are described. In one example, an amplifier includes an amplifier cell, and a biasing network coupled to the common gate transistor in the amplifier cell. The amplifier cell includes a common source transistor and a common gate transistor in a cascode arrangement, where at least one of the common source transistor and the common gate transistor comprises a field plate. Among other advantages, the amplifiers described herein can be biased with relatively high voltages and still operate like a single a common source transistor, without sacrificing reliability, performance, or requiring additional off-chip components, such as biasing networks of resistors and inductors.

Methods and apparatus for implementing a power efficient amplifier device through the use of a main (primary) and auxiliary (secondary) power amplifier are described. The primary and secondary amplifiers operate as current sources providing current to the load. Capacitance coupling is used to couple the primary and secondary amplifier outputs. In some embodiments the combination of primary and secondary amplifiers achieve high average efficiency over the operating range of the device in which the primary and secondary amplifiers are used in combination as an amplifier device. The amplifier device is well suited for implementation using CMOS technology, e.g., N-MOSFETs, and can be implemented in an integrated circuit space efficient manner that is well suited for supporting RF transmissions in the GHz frequency range, e.g., 30 GHz frequency range. The primary amplifier in some embodiments is a CLASS-AB or B amplifier and the secondary amplifier is a CLASS-C amplifier.

A transmission apparatus is provided with: a plurality of amplification units that amplify RF signals arranged in at least 2 bands; a first control unit that selects amplification units that perform an amplification operation, from among the plurality of amplification units, in accordance with total power of RF signals to be transmitted; a second control unit which, in accordance with a power ratio of the RF signals to be transmitted in respective bands, changes the power ratio of the RF signals in the respective bands while keeping constant the total power of the RF signals received at each of the selected amplification units; and a combining unit that combines the RF signals outputted by the selected amplification units.