An embodiment of the present disclosure relates to a method of controlling a power amplifier (PA). The PA can comprise a main PA path and an auxiliary PA path. The auxiliary PA path can have a plurality of turn-on settings. The method can comprise: determining a power back off gain and a lower bound gain for the PA; and performing an iterative auxiliary PA turn-on setting selection process. The selection process can comprise: determining an instantaneous power input to the PA; based on the instantaneous power input, choosing a turn-on setting in the plurality of turn-on settings of the auxiliary PA path that causes an instantaneous gain of the PA to be between the power back off gain and the lower bound gain; and applying the chosen turn-on setting to the auxiliary PA path.

Apparatus and methods for power detection with enhanced dynamic range are provided. In certain embodiments, a front end system includes a power amplifier that amplifies a radio frequency (RF) input signal to generate an RF output signal, a directional coupler that generates a sensed RF signal based on sensing the RF output signal from the power amplifier, and a power detector that processes the sensed RF signal to generate a detection signal indicating an output power of the power amplifier. Additionally, the power detector includes two or more detection paths providing different amounts of gain to the sensed RF signal from the directional coupler.

A method, apparatus and computer program is described comprising: determining an absolute gain of a power amplifier over time, wherein the absolute gain is formed from the division of a feedback baseband signal derived (e.g. by demodulating an RF signal) from an output of the power amplifier, by a forward baseband signal that is used to form an input of the power amplifier; determining a relative gain transient response (GTR) of the power amplifier, by normalising the absolute gain to generate a relative gain of the power amplifier over time; and determining a transient response compensation value having inverse characteristics to the relative gain transient response.

Radio frequency (RF) generators are disclosed. A RF generator may include a modulator configured to receive an arbitrary waveform and an RF carrier, and generate a pulsed radio frequency (RF). The arbitrary waveform may be generated via an analog signal generator external to the RF generator. Further, the RF generator may include an amplification stage configured to amplify the pulsed RF signal. RF generation systems and methods of generating a pulsed RF signal also disclosed.

Disclosed in the present invention are a radio frequency power amplifier, a radio frequency front-end module, and a communication terminal. The power amplifier includes a control unit, a power amplification unit, a detection and comparison unit, and a gain adjustment unit. According to a function relationship between the gain of the power amplification unit and the output power of the power amplification unit in different frequency bands and different power level modes, the control unit adjusts a function relationship between an adjustment current generated by the gain adjustment unit and a bias current of the power amplification unit; then the detection and comparison unit compares the bias current, of the power amplification unit with a reference current; according to the comparison result, the control unit controls whether the gain adjustment unit needs to generate an adjustment current and output the same to the power amplification unit.

A symbol-power-tracking (SPT) voltage supply to power a radio-frequency power amplifier (RF PA) is shown. A power converter is coupled to an output port of an input power source for power conversion, and has an output terminal coupled to a power terminal of the RF PA. A transition capacitor is coupled to the power terminal of the radio-frequency power amplifier through the output terminal of the power converter. An assisted charging and discharging circuit is coupled to the transition capacitor during cyclic prefix (CP) sections. A multi-level array is provided which includes a plurality of voltage-regulated capacitors pre-charged to and kept at different voltage levels. During each symbol section, a target capacitor at a fixed voltage level matching the current SPT situation is selected from among the voltage-regulated capacitors to be coupled to the power terminal of the radio-frequency power amplifier.

Examples disclosed herein relate to a high gain active relay antenna system. The active relay antenna system comprises a first antenna pair having a first receive antenna and a first transmit antenna to communicate wireless signals in a forward link from a base station to a plurality of users; and a second antenna pair having a second receive antenna and a second transmit antenna to communicate wireless signals in a return link from the plurality of users to the base station. The active relay antenna system further comprises a first active relay section and a second active relay section to provide for adjustable power gain in the wireless signals.

A current feedback amplifier (CFA). The CFA includes a common-gate input stage, a biasing circuitry, and a differential pair coupled in parallel between the supply voltage node and the reference voltage node. The common-gate input stage amplifies an input signal received at an input node and supplies it to a gate of the complementary transistors of the differential pair. The biasing circuitry supplies a bias voltage to a gate of the transistors of the common-gate input stage. The input node of the common-gate input stage and a node between the complementary transistors in the first path of the differential pair are shorted.

A time to digital converter has a counter, a first phase difference detector, a first capacitor, a second capacitor having capacitance N times a capacitance of the first capacitor, a comparator to compare a charge voltage of the first capacitor with a charge voltage of the second capacitor, a first charge controller, a first phase difference arithmetic unit, a second phase difference detector, a second charge controller, a second phase difference arithmetic unit to operate the phase difference between the first signal and the second signal, and a third phase difference arithmetic unit to detect a fractional phase difference between the first signal and the second signal. The first phase difference arithmetic unit operates the phase difference between the first signal and the second signal, based on a reference phase, when the counter suspends a measurement operation.

Polyphase power amplifiers for load insensitivity are disclosed. In certain embodiments, a polyphase transmit system includes an intermediate frequency transceiver including a first complex mixer that outputs a plurality of intermediate frequency transmit signals of different phases, and an intermediate frequency to radio frequency module including a second complex mixer that generates a plurality of radio frequency transmit signals of different phases based on the plurality of intermediate frequency transmit signals, and a polyphase power amplifier that receives the plurality of radio frequency transmit signals and outputs an amplified radio frequency signal. The polyphase transmit system further includes an antenna that transmits the amplified radio frequency signal.