A power amplifier comprising: a first amplifier; a second amplifier, wherein the first and second amplifiers are arranged in parallel; an analogue pre-distortion network; a first coupler; and a second coupler, wherein the first coupler is configured to receive an input signal, direct said input signal to the first amplifier, and direct a first pre-distortion signal to the analogue pre-distortion network, wherein the first pre-distortion signal comprises a first distortion component generated at the input of the first amplifier, and the analogue pre-distortion network is configured to receive the first pre-distortion signal and manipulate its amplitude and/or phase to obtain a manipulated first pre-distortion signal, and the second coupler is configured to direct the manipulated first pre-distortion signal to the second amplifier.

Low noise amplifiers (LNAs) are disclosed herein. In certain embodiments, an LNA includes an input balun configured to convert a single-ended radio frequency (RF) receive signal to a differential RF receive signal, an amplifier chain configured to amplify the differential RF receive signal to generate a differential amplified RF receive signal, and an output balun configured to convert the differential amplified RF receive signal into a single-ended amplified RF receive signal. The LNA's amplifier chain is operable in multiple gain modes, and includes a first differential amplification stage, a second differential amplification stage, and a third differential amplification stage.

A power amplifier comprises a first transistor, a first transformer, a first variable resistor, a first bias circuit and coupling circuitry configured to couple the first transformer, a first end of the first variable resistor, and a collector of the first transistor at a first node, the first transformer and a second end of the first variable resistor at a second node, and the bias circuit and a base of the first transistor at a third node.

A decrease in isolation is suppressed when transmitting both a first transmission signal and a second transmission signal in simultaneous communication. A radio frequency module includes a first transformer and a second transformer. The first transformer is included in a first differential power amplifier to amplify the first transmission signal. The second transformer is included in a second differential power amplifier to amplify the second transmission signal to be simultaneously communicated with the first transmission signal. A direction of magnetic flux generated in the first transformer is different from a direction of magnetic flux generated in the second transformer.

In a power amplifying module in which a plurality of differential amplifying circuits is mounted on a substrate, each of the differential amplifying circuits includes a chip device that includes at least two amplifiers, each of the at least two amplifiers amplifying a differential signal, a balun that includes a primary side winding wire and a secondary side winding wire, both ends of the primary side winding wire being connected to an output of the chip device, and a capacitor provided between a power feed point of the primary side winding wire and a reference potential. In at least one of the plurality of the differential amplifying circuits, the distance from one end of the primary side winding wire to the power feed point is different from the distance from the other end of the primary side winding wire to the power feed point.

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.

An improved transformer based switch for PALNA applications. The transformer based switch having an input single pole port and a circuit with at least one transformer and at least one switch configured to connect portions of the transformer to ground or to short the transformer. The primary side of the transformer being connected to the input port and the secondary side of the transformer being connected to an output port.

Aspects of the present disclosure provide a circuit configured to adjust an input impedance of an amplifier such as a low-noise amplifier. In certain aspects, the circuit is coupled to a node, wherein the node is between a first transistor and a second transistor of the amplifier. The circuit may include an inductor and a capacitor coupled in series, wherein the inductor is coupled with one or more load inductors of the amplifier through negative magnetic coupling.

An on-chip transformer circuit is disclosed. The on-chip transformer circuit comprises a primary winding circuit comprising at least one turn of a primary conductive winding arranged as a first N-sided polygon in a first dielectric layer of a substrate; and a secondary winding circuit comprising at least one turn of a secondary conductive winding arranged as a second N-sided polygon in a second, different, dielectric layer of the substrate. In some embodiments, the primary winding circuit and the secondary winding circuit are arranged to overlap one another at predetermined locations along the primary conductive winding and the secondary conductive winding, wherein the predetermined locations comprise a number of locations less than all locations along the primary conductive winding and the secondary conductive winding.

A push-push frequency doubler based on complementary transistors is provided. The first differential amplifier circuit receives a differential input signal having an initial frequency, and amplifies the amplitude of the second harmonic of the differential input signal to obtain a first signal. The second differential amplifier circuit receives the differential input signal with the initial frequency and amplifies the amplitude of the second harmonic of the differential input signal to obtain the second signal. Where, the first signal and the second signal are a set of differential signals with the same amplitude and a phase difference of 180°. The output load circuit extracts the second harmonic signal in the first and second signal respectively to obtain and output a pair of differential output signal with first output frequency whose value is twice of the initial frequency. As a result, the frequency doubler with differential output signal is realized.