Patent classifications
H03F1/3276
Power amplifier equalizer
Circuits and methods for achieving good AM-AM and AM-PM metrics while achieving good power, PAE, linearity, and EVM performance in an amplifier. Embodiments provide an equalization approach which compensates for AM-AM and AM-PM variations in an amplifier by controlling bias voltage versus output power to alter the AM-AM and AM-PM profiles imposed by the amplifier. Differential amplifier embodiments include cross-coupled common-gate transistors that generate an equalization voltage that alters the gate bias voltage of respective main FETs in proportion to a power level present at the respective drains of the main FETs. Single-ended amplifier embodiments include an equalization circuit that alters the bias voltage to the gate of a main FET in proportion to a power level present at the main FET drain. Embodiments may also include a linearization circuit which alters the AM-PM profile of an input signal to compensate for the AM-PM profile imposed by a coupled amplifier.
Configurable non-linear filter for digital pre-distortion
Some embodiments herein describe a radio frequency communication system that can include a transmitter to output an radio frequency (RF) transmit signal, the transmitter including a digital pre-distortion system (DPD) that pre-distorts the RF transmit signal. The DPD system can include a configurable non-linear filter, such as a Laguerre filter, having multiple rows where at least one row operates with a configurable decimation ratio. The DPD system can further include decimators and a crossbar switch coupled between the decimators.
SIGNALING OF INFORMATION FOR NON-LINEARITY MODEL
Aspects relate to signaling relating to a non-linearity model for power amplifier circuitry of a transmitting device. The power amplifier circuitry may apply digital pre-distortion (DPD) to a signal prior to amplification and transmission of the signal. A receiving device may apply digital post-distortion (DPoD) to a signal received from the transmitting device where the DPoD is based on the non-linearity model. The transmitting device may send to the receiving device non-linearity parameters for the non-linearity model.
Radio frequency receiver, radio frequency transmitter, and communications device
A radio frequency transmitter includes N transmit channels, where each transmit channel includes one nonlinear module, a primary correction circuit, coupled to each of N nonlinear modules that correspond to the N transmit channels, and configured to provide a primary correction signal for the N nonlinear modules, and N secondary correction circuits, where the N secondary correction circuits are coupled to the N nonlinear modules respectively, and each secondary correction circuit is configured to provide a secondary correction signal for a nonlinear module coupled to the secondary correction circuit.
Power Amplifier Equalizer
Circuits and methods for achieving good AM-AM and AM-PM metrics while achieving good power, PAE, linearity, and EVM performance in an amplifier. Embodiments provide an equalization approach which compensates for AM-AM and AM-PM variations in an amplifier by controlling bias voltage versus output power to alter the AM-AM and AM-PM profiles imposed by the amplifier. Differential amplifier embodiments include cross-coupled common-gate transistors that generate an equalization voltage that alters the gate bias voltage of respective main FETs in proportion to a power level present at the respective drains of the main FETs. Single-ended amplifier embodiments include an equalization circuit that alters the bias voltage to the gate of a main FET in proportion to a power level present at the main FET drain. Embodiments may also include a linearization circuit which alters the AM-PM profile of an input signal to compensate for the AM-PM profile imposed by a coupled amplifier.
Common mode rejection for differential receiver in high speed data channel
A common-mode rejection receiver including a first differential amplifier arranged to receive a differential signal including receiving a positive signal of the differential signal at a first non-inverting input port and receiving a negative signal of the differential signal at a first inverting input port, and output a first differentiated signal based on a voltage differential between the positive signal and the negative signal. A clamping circuit is arranged to limit a magnitude of the first differentiated signal to a pre-determined limit. A second differential amplifier is arranged to receive the positive signal at a second inverting input port and receive the negative signal at a second non-inverting input port, and output a second differentiated signal. A matching circuit is arranged to receive the second differentiated signal output and output a matched signal. A summing circuit adds the clamped signal and matched signal and outputs a receiver output signal.
Power Amplifier Linearizer
Circuits and methods for achieving good amplifier AM-AM and AM-PM metrics while achieving good power, PAE, linearity, and EVM performance. Embodiments compensate for a non-linear distortion profile (e.g., an AM-PM and/or AM-AM profile) in an amplifier by pre-processing an input signal, such as a radio-frequency signal, to alter the non-linear distortion profile of the input signal so as to compensate for the non-linear distortion profile imposed by a coupled device, such as an amplifier. An inventive aspect includes linearizing an output from an amplifier having a first non-linear distortion profile, including passing an input signal having a second non-linear distortion profile through a reflective hybrid coupler to a non-linear termination circuit, and reflecting a modified input signal from the non-linear termination circuit back through the reflective hybrid coupler as an output signal, the output signal having a third non-linear distortion profile shaped to compensate for the first non-linear distortion profile.
SEMICONDUCTOR DEVICE
A semiconductor device includes an input terminal, an output terminal, an amplifier with an input, and a predistorter with an input electrically coupled to the input terminal and with an output electrically coupled to the input of the amplifier. The predistorter includes a first transistor.
COMMON MODE REJECTION FOR DIFFERENTIAL RECEIVER IN HIGH SPEED DATA CHANNEL
A common-mode rejection receiver including a first differential amplifier arranged to receive a differential signal including receiving a positive signal of the differential signal at a first non-inverting input port and receiving a negative signal of the differential signal at a first inverting input port, and output a first differentiated signal based on a voltage differential between the positive signal and the negative signal. A clamping circuit is arranged to limit a magnitude of the first differentiated signal to a pre-determined limit. A second differential amplifier is arranged to receive the positive signal at a second inverting input port and receive the negative signal at a second non-inverting input port, and output a second differentiated signal. A matching circuit is arranged to receive the second differentiated signal output and output a matched signal. A summing circuit adds the clamped signal and matched signal and outputs a receiver output signal.
Feedback amplifier as an impedance modulator for a linear power amplifier
A power amplifier and power amplification circuit are described herein. An illustrative power amplifier is disclosed to include an input terminal, a drive amplifier connected to the input terminal, and an impedance modulator having a capacitance that is adjusted inversely and proportionately relative to a signal output by the drive amplifier, wherein the impedance modulator provides a feedback loop between an output of the drive amplifier and the input terminal.