There is provided a power amplifier arrangement for amplifying an input power signal to an output power signal. The power amplifier arrangement comprises a main amplifier having an input and an output. The power amplifier arrangement comprises at least one auxiliary amplifier, each having an input and an output. The power amplifier arrangement comprises a power divider having an input and outputs. The input of the power divider is configured to receive the input power signal. Each output of the power divider is connected to a respective input of the power amplifiers. The power amplifier arrangement comprises a Doherty combiner comprising at least one Ruthroff transformer and configured to combine all the outputs of the power amplifiers to, at an output of the Doherty combiner, produce the output power signal.

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.

An amplifier that is configured to amplify an RF signal includes a power combiner circuit. The power combiner circuit includes a first branch connected between a first RF input port and a summing node and a second branch connected between a second RF input port and the summing node. Each of the first and second branches includes an impedance inverter. The Chireix combiner is configured to present a Chireix load modulated impedance response to the first and second RF input ports. The power combiner circuit further includes compensation elements being configured to at least partially compensate for a reactance of the Chireix combiner circuit in a Doherty amplifier mode in which a signal is applied to the first RF input port and the second RF input port is electrically open.

A radio frequency (RF) power amplifier includes an amplifying stage that includes an amplifying module, an input module and a feedback module. The amplifying module receives an RF to-be-amplified signal, and performs power amplification on the RF to-be-amplified signal to generate an RF output signal. The input module receives an RF input signal. The feedback module receives the RF output signal, cooperates with the input module to provide the RF to-be-amplified signal based on the RF input and output signals, and cooperates with the amplifying module to forma positive feedback loop that provides a loop gain which is less than one.

A power amplifier includes an outphasing amplifier. The outphasing amplifier includes a first amplifier and a second amplifier, and is configured to provide a first amplified RF signal and a second amplified RF signal that is phase shifted from the first amplified RF signal. The power amplifier further includes an output circuit that is configured to combine RF power of the first and second amplified RF signals at a summing node. The output circuit includes a first branch connected between the first amplifier and a summing node and a second branch connected between the second amplifier and the summing node. The first and second branches are each configured to match an output impedance of the first and second amplifiers and to phase shift the first and second amplified RF signals for an outphasing operation using common reactive components for the match of the output impedance and the outphasing operation.

A power amplifier is described that includes a balanced amplifier arrangement having an input quadrant coupler and output quadrant coupler and two amplifiers, which may include or consist of single transistors, there between. The power amplifier also can provide a signal to an isolated port of the output coupler in order to provide impedance matching. This arrangement dispenses with the need for transistor matching networks at the output of the two amplifiers, which in turn enables the power amplifier to be operable over a wider frequency range as compared with a Doherty power amplifier.

An amplifier, communication device and method of amplification are disclosed. An RF signal is amplified by a Doherty power amplifier (DPA). The DPA has a main amplifier with a Class-AB amplifier in parallel with a Class-C amplifier. When the RF signal power is smaller than 6 dB PBO, the Class-AB amplifier provides the main amplifier amplification; when the RF signal is between 6 dB PBO and 0 dB PBO, both the Class-AB and Class-C amplifiers provide the main amplifier amplification.

An RF power amplifier circuit includes a power divider, multiple power amplification circuits and a power combiner that cooperatively perform power amplification on an RF input signal so as to output an RF output signal, and an impedance conversion circuit that has a circuit terminal coupled to one of the power divider and the power combiner which has a microstrip structure, and that is configured such that a conversion impedance, which is an impedance seen into the impedance conversion circuit from the circuit terminal, matches an impedance seen into the power divider or the power combiner from the circuit terminal. The microstrip structure has a physical length associated with the conversion impedance.

A distributed active transformer includes an input transformer set and an output transformer set. Active stages are coupled between a transformer in the input transformer set and a transformer in the output transformer set. The input and output transformer sets are each configured as a slab transformer. The input slab transformer includes a single primary slab and many secondary slabs. The output slab transformer includes many primary slabs and a single secondary slab.

Package assemblies for improving heat dissipation of high-power components in microwave circuits are described. A laminate that includes microwave circuitry may have cut-outs that allow high-power components to be mounted directly on a heat slug below the laminate. Electrical connections to circuitry on the laminate may be made with wire bonds. The packaging allows more flexible design and tuning of packaged microwave circuitry.