A MIM capacitor is included in any one or more of a first matching circuit and a second matching circuit. The mat capacitor performs impedance matching of a fundamental wave included in a high-frequency signal with a transmission line, and forms a short-circuit point for a harmonic included in the high-frequency signal at a connection point with the transmission line.

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.

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.

A stripline radial power combiner is provided. The stripline radial combiner comprises a first stripline level comprising N radial combiner arms coupled to a first common node; a second stripline level comprising a common port coupled to a second common node; wherein the first stripline level is mounted over the second stripline level; and wherein the first common node and the second common node are coupled by a conductive via through the first stripline level and the second stripline level.

An RF power amplifier is described including a first amplifier and a second amplifier arranged in parallel between an RF power amplifier input and an RF power amplifier output. A phase adjuster adjusts the phase of a signal on at least one of the first amplifier signal path and the second amplifier signal path. A first impedance inverter has a first impedance inverter input coupled to an output of the second amplifier and a first impedance inverter output coupled to the RF power amplifier output. The RF power amplifier is configured to enable at least one of the first amplifier and the second amplifier dependent on an operation mode and the first impedance inverter is configured to modulate the load impedance of the second amplifier in response to the operation mode changing.

A microwave amplifier having a load network which provides more efficient amplification of a low power microwave frequency signal. The amplifier comprises a transistor and a load network coupled to the transistor output to shape a waveform of an amplified microwave signal at the transistor current source plane. The load network comprises: a fundamental matching network to provide impedance matching at a fundamental frequency; a half-wave transmission line for a second harmonic frequency disposed between the transistor output and the fundamental matching network; a quarter-wave stub and a five-quarter-wave stub for a third harmonic frequency arranged on the half-wave transmission line to provide an open circuit condition at the third harmonic; and a quarter-wave stub for the second harmonic frequency and a quarter-wave stub for the fundamental frequency, arranged on the half-wave transmission line to provide a short circuit condition at the second harmonic frequency.

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.

Antenna waveguide transitions for solid state power amplifiers (SSPAs) are disclosed. An SSPA includes a waveguide channel that is configured to propagate an input signal, such as an electromagnetic signal, from an input port to a solid state amplifier for amplification. The waveguide channel is further configured to propagate an amplified signal from the solid state amplifier to an output port. Waveguide transitions to and from the solid state amplifier are bandwidth matched to the waveguide channel. Additionally, the waveguide transitions may be thermally coupled to the waveguide channel. The waveguide transitions may include antenna structures that have a signal conductor and a ground conductor. In this manner, the SSPA may have improved broadband coupling as well as improved thermal dissipation for heat generated by the solid state amplifier.

Spatial power-combining devices and, in particular, spatial power-combining devices with filtering elements are disclosed. A spatial power-combining device includes a plurality of amplifier assemblies and each amplifier assembly includes an input antenna structure, an amplifier, an output antenna structure, and a filtering element. A filtering element may be an integral single component with an input signal conductor of the input antenna structure or an integral single component with an output signal conductor of the output antenna structure. In some aspects, a filtering element may be an integral single component with both the input signal conductor and the output signal conductor.

Antenna waveguide transitions for solid state power amplifiers (SSPAs) are disclosed. An SSPA includes a waveguide channel that is configured to propagate an input signal, such as an electromagnetic signal, from an input port to a solid state amplifier for amplification. The waveguide channel is further configured to propagate an amplified signal from the solid state amplifier to an output port. Waveguide transitions to and from the solid state amplifier are bandwidth matched to the waveguide channel. Additionally, the waveguide transitions may be thermally coupled to the waveguide channel. The waveguide transitions may include antenna structures that have a signal conductor and a ground conductor. In this manner, the SSPA may have improved broadband coupling as well as improved thermal dissipation for heat generated by the solid state amplifier.