Techniques for controlling the output of a power amplifier are disclosed. In one embodiment, the techniques may be realized as a system that includes a power amplifier and a controller coupled to the power amplifier to form a feedback loop. The power amplifier is enabled or disabled in response to a blanking signal. The controller includes an accumulator that stores an accumulated error of the feedback loop. The controller suspends operation of the accumulator when (1) a level of the input signal is below a first threshold for an amount of time that exceeds a second threshold, (2) the blanking signal indicates that the power amplifier is disabled, or (3) both. The controller resumes operation of the accumulator when (1) the level of the input signal is above the first threshold and (2) the blanking signal indicates that the power amplifier is enabled.

A RF-digital hybrid mode power amplifier system for achieving high efficiency and high linearity in wideband communication systems is disclosed. The present invention is based on the method of adaptive digital predistortion to linearize a power amplifier in the RF domain. The present disclosure enables a power amplifier system to be field reconfigurable and support multi-modulation schemes (modulation agnostic), multi-carriers and multi-channels. As a result, the digital hybrid mode power amplifier system is particularly suitable for wireless transmission systems, such as base-stations, repeaters, and indoor signal coverage systems, where baseband I-Q signal information is not readily available.

A circuit and computer implemented method tunes an RF switching power amplifier circuit for an antenna by receiving a measurement of reflected RF signal from the antenna, receiving a measurement of current provided to the circuit from a power source, receiving a measurement of RF power provided to the antenna, adjusting a tunable antenna circuit responsive to the measurement of reflected RF signal, and adjusting a first capacitor capacitance value and a second capacitor capacitance value of a waveform shaping circuit in response to the received measurement of current and RF power.

Envelope tracking systems for power amplifiers are provided herein. In certain embodiments, an envelope tracker is provided for a power amplifier that amplifies an RF signal. The envelope tracker includes an error amplifier that controls a voltage level of a power amplifier supply voltage of the power amplifier based on amplifying a difference between a reference signal and an envelope signal indicating an envelope of the RF signal. The envelope tracker further includes a multi-level switching circuit that generates an error amplifier supply voltage based on sensing a current of the error amplifier, and uses the error amplifier supply voltage to power the error amplifier.

A signal compensation device is disclosed. The signal compensation device includes an operation circuit and a modulation circuit. The operation circuit is configured to generate a control signal according to a first data signal and a second data signal, in which the second data signal is generated according to the first data signal by a signal conversion circuit. The modulation circuit is configured to provide a loop gain according to the control signal to compensate an attenuation of the signal conversion circuit.

An approach to predistortion of a first set of signals for an antenna array allows beam-steering without corrupting spectrum away from the main beam and where other users may be located. In some implementations, the predistorter uses fewer than one predistorter per signal (i.e., per power amplifier or per antenna), and/or has the computational complexity of such fewer predistorters, to generate predistortions of the first set of signals for amplification and transmission via the antenna array.

An output power control device includes: an attenuator to attenuate power of a high-frequency signal output from an oscillator; a high-frequency power amplifier to amplify the power of the high-frequency signal output from the attenuator; a monitor circuit to monitor the power of the high-frequency signal output from the high-frequency power amplifier; and a controller to control an attenuation amount of the attenuator based on the monitor signal output from the monitor circuit or based on attenuation amount setting data from a data unit. The oscillator generates the high-frequency signal in synchronization with a trigger signal. The controller starts control of the attenuation amount of the attenuator based on the attenuation amount setting data, in synchronization with the trigger signal, and, after receiving the monitor signal, the controller controls the attenuation amount of the attenuator based on the monitor signal.

Disclosed are an electronic impedance tuning apparatus for measuring a load-pull of a mobile amplifier and an electronic impedance tuning method therefor. An electronic impedance tuning apparatus according to one embodiment of the present invention comprises: a coupler for transferring, to transmission lines respectively connected to a through port and a coupled port, an input voltage inputted to an input port; a magnitude part for controlling a change in the magnitude of the impedance through a change in length difference of the transmission lines; and a phase part for controlling a change in the phase of the impedance through an equal length change of the transmission lines.

A high directivity compact size inter-layer coupler that has application for coupling off a pre-distortion coupling signal from a main signal at an output of a power amplifier to a pre-distortion circuit. The coupler includes a main signal line formed on a surface of a first dielectric layer opposite to a second dielectric layer, where the main signal line receives the main signal, and a coupling line formed between the second dielectric layer and a third dielectric layer, where the coupling line is electromagnetically coupled to the main line so as to generate the coupling signal thereon. The coupling line has a general U-shape including a first leg portion, a second leg portion and a transverse portion between the first and second leg portions. The transverse portion includes a plurality of spaced apart blocks coupled together by a narrow line portion.

An RF receiver circuit configuration and design limited by conditions and frequencies to simultaneously provide steady state low-noise signal amplification, frequency down-conversion and image signal rejection. The invention provides combined circuits of an RF transceiver architecture that measure antenna reflected power relative to forward power using the error amplifier signal to adjust the gain of the variable gain amplifier in order to compensate for the mismatch between forward reflected power and forward power at the antenna in order to achieve constant radiated power. The RF receiver circuit may be implemented as one of a CMOS single chip device or as part of an integrated system of CMOS components.