A Spatial Power Combining Amplifier (SPCA) exhibiting a new concept for the amplification of coherent (e.g., microwave) radiation. A general description of the SPCA a power analysis at various SPCA stages is provided. A successfully tested S-band SPCA example was able to deliver 120 W of power with a gain of 50 dB and 50 percent efficiency.

Various embodiments include a power amplifier with crest factor reduction embodied by first circuitry for producing a correlated out-of-band noise signal for controlling the adjacent channel leakage ratio (ACLR) of a communication device; and second circuitry for providing an output signal for controlling the error vector magnitude (EVM) of a digital radio. The ACLR and the EVM are concurrently individually controllable. Additional apparatus is described.

Various embodiments include a power amplifier with crest factor reduction embodied by first circuitry for producing a correlated out-of-band noise signal for controlling the adjacent channel leakage ratio (ACLR) of a communication device; and second circuitry for providing an output signal for controlling the error vector magnitude (EVM) of a digital radio. The ACLR and the EVM are concurrently individually controllable. Additional apparatus is described.

A very high frequency (VHF) transceiver can include an amplitude and phase shift keying (APSK) modulator configured to modulate signals for transmission across a first VHF channel of a plurality of VHF channels used to communicate between or among aircraft and one or more ground stations. Each of the VHF channels can have a bandwidth of at least 8.33 kilo Hertz (kHz) with a data rate per Hertz (Hz) greater than or equal to 3 bits per second per Hz (bps/Hz). The VHF transceiver can include a power amplifier configured to amplify the modulated signals prior to the transmission. The VHF transceiver can include a linearity controller configured to control linearity of the power amplifier according to at least one of a Cartesian feedback amplifier linearization, pre-distortion amplifier linearization or feedforward amplifier linearization to mitigate nonlinear distortion associated with signals output by the power amplifier.

Disclosed is a Doherty power amplifier. At least one power amplification tube and other power amplification tubes in the Doherty power amplifier are located in different planes.

Disclosed is a Doherty power amplifier. At least one power amplification tube and other power amplification tubes in the Doherty power amplifier are located in different planes.

A curve fitting circuit, an analog predistorter, and a radio frequency signal transmitter are disclosed. Each segmentation processing circuit in the curve fitting circuit generates a to-be-processed signal according to a intercepted part of a received signal, and generates q output signals according to the to-be-processed signal. Parts intercepted by different segmentation processing circuits are not exactly the same. Each first adder circuit in the curve fitting circuit receives one signal in the q output signals of each segmentation processing circuit, and obtains one output signal of the curve fitting circuit according to a sum of received n signals.

A curve fitting circuit, an analog predistorter, and a radio frequency signal transmitter are disclosed. Each segmentation processing circuit in the curve fitting circuit generates a to-be-processed signal according to a intercepted part of a received signal, and generates q output signals according to the to-be-processed signal. Parts intercepted by different segmentation processing circuits are not exactly the same. Each first adder circuit in the curve fitting circuit receives one signal in the q output signals of each segmentation processing circuit, and obtains one output signal of the curve fitting circuit according to a sum of received n signals.

Disclosed herein is a DC offset cancellation circuit. The DC offset cancellation circuit includes a DC feedback unit configured to vary a DC feedback (DCFB) bandwidth to add at least one mid-bandwidth to the DCFB bandwidth and to provide a delay time in each case in order to reduce the DC droop error that occurs in switching from the high bandwidth (BW) to the mid-BW or from the mid-BW mode to the low BW mode, such that stable settling is ensured.

A device configured to perform wireless communication includes: a pre-distortion circuit configured to generate a pre-distorted input signal by performing pre-distortion on an input signal based on a parameter set comprising a plurality of coefficients; a power amplifier configured to generate an output signal by amplifying an RF signal based on the pre-distorted input signal; and a parameter obtaining circuit configured to obtain second memory polynomial modeling information corresponding to an operating frequency band based on first memory polynomial modeling information corresponding to each of a plurality of frequency sections and obtain a parameter set according to an indirect learning structure by using the second memory polynomial modeling information.