A high-frequency front end circuit includes an antenna terminal, a reception circuit that is directly or indirectly connected to the antenna terminal, and a transmission circuit that is directly or indirectly connected to the antenna terminal, wherein the transmission circuit has an amplification circuit, the amplification circuit includes an input terminal and an output terminal, an amplification element provided on a path connecting the input terminal and the output terminal, and a bias circuit having an LC resonance circuit and connected to between the amplification element and the output terminal. A frequency pass band of the transmission circuit is lower than a frequency pass band of the reception circuit, and a value of a resonant frequency of the bias circuit is smaller than a value of a frequency pass band width of the transmission circuit.

A power amplifier includes a two-dimensional matrix of NM active cells formed by stacking main terminals of multiple active cells in series. The stacks are coupled in parallel to form the two-dimensional matrix. The power amplifier includes a driver structure to coordinate the driving of the active cells so that the effective output power of the two-dimensional matrix is approximately NM the output power of each of the active cells.

A differential constructive wave oscillator device including a single, continuous differential transmission line that is arranged into first and second parallel traces in the form of a Mobius loop. The continuous transmission line includes first and second crossover points, each of which provides for a point of inflection between the first and second traces. In each stage of the device, both the first and second traces of the transmission line carry the forward traveling wave signal from a differential input port to a differential output port. Each phase includes a differential delay section that provides for a phase shift between a signal on the first trace and a signal on the second trace. Each phase additionally includes a differential feedback amplifier that amplifies the forward traveling wave signal at the differential output port, generates a differential feedback signal, and routes the differential feedback signal to the differential input port.

A distributor distributes an input signal to a first transmission line and a second transmission line. A high-pass filter, a first linearizer, and a first phase shifter disposed on the first transmission line adjust the phase and amplitude of an intermodulation distortion in a low-frequency range. A low-pass filter, a second linearizer, and a second phase shifter disposed on the second transmission line adjust the phase and amplitude of an intermodulation distortion in a high-frequency range. A synthesizer synthesizes the signal from the first transmission line and the signal from the second transmission line.

An amplifier arrangement comprises N amplifier stages comprising a main amplifier stage and a plurality of peaking amplifier stages. A transmission line comprises a varying impedance for transforming a load impedance to a higher impedance at the main amplifier stage, wherein the plurality of peaking amplifiers are coupled at intermediate locations to the transmission line. The amplifier arrangement is configured such that at least two of the peaking amplifiers are collectively driven with time delayed versions of substantially the same signal. The amplifier arrangement may be configured to operate with N2 or fewer transition points in a Doherty mode of operation. As such, the amplifier arrangement may comprise more amplifier stages than are necessarily required in a Doherty amplifier arrangement having the same number of transition points.

A power amplifier includes a transistor operating in a range of frequencies from a lower operating frequency to a higher operating frequency to provide a relatively linear gain between the lower operating frequency and the higher operating frequency, an input transmission line circuit coupled to a gate terminal of the transistor, and an output transmission line circuit coupled to a drain terminal of the transistor. The input transmission line includes an inductor-capacitor (LC) circuit that resonates at a first resonant frequency equaled to or higher than the higher operating frequency. The output transmission line includes an inductor-capacitor-inductor (LCL) circuit and a capacitor-inductor-capacitor (CLC) circuit. The LCL circuit resonates at a second resonant frequency equaled to or lower than the lower operating frequency. The CLC circuit resonates at a third resonant frequency equaled to or higher than the higher operating frequency.

A high-frequency front end circuit includes an antenna terminal, a reception circuit that is directly or indirectly connected to the antenna terminal, and a transmission circuit that is directly or indirectly connected to the antenna terminal, wherein the transmission circuit has an amplification circuit, the amplification circuit includes an input terminal and an output terminal, an amplification element provided on a path connecting the input terminal and the output terminal, and a bias circuit having an LC resonance circuit and connected to between the amplification element and the output terminal. A frequency pass band of the transmission circuit is lower than a frequency pass band of the reception circuit, and a value of a resonant frequency of the bias circuit is smaller than a value of a frequency pass band width of the transmission circuit.

A power source supply circuit includes: a plurality of power sources (11-1, 11-2) that generate power source voltages different from each other; a switch circuit (14) that switches and outputs the power source voltages generated in the plurality of power sources (11-1, 11-2); a voltage output terminal (16) that outputs outside the power source voltages output from the switch circuit (14); an RF choke circuit (15) provided between the switch circuit (14) and the voltage output terminal (16), the RF choke circuit (15) including a first capacitor; and a second capacitor (12-1, 12-2) provided between the plurality of power sources (11-1, 11-2) and the switch circuit (14), the second capacitor (12-1, 12-2) having a larger capacitance than the first capacitor.

A power amplifier includes a two-dimensional matrix of NM active cells formed by stacking main terminals of multiple active cells in series. The stacks are coupled in parallel to form the two-dimensional matrix. The power amplifier includes a driver structure to coordinate the driving of the active cells so that the effective output power of the two-dimensional matrix is approximately NM the output power of each of the active cells.

Apparatus and methods for multi-mode power amplifiers are provided herein. In certain configurations, a wireless device includes a multi-mode power amplifier including a plurality of amplification paths electrically connected in parallel with one another. The plurality of amplification paths includes a first amplification path including an input stage of a first stage type and an output stage of a second stage type, and a second amplification path including an output stage of the second stage type. The first stage type provides non-inverting gain and the second stage type provides inverting gain. The wireless device further includes a transceiver that provides a radio frequency signal to the multi-mode power amplifier, and that operates the multi-mode power amplifier in a selected power mode chosen from a plurality of power modes based on selectively activating one or more of the plurality of amplification paths.