A communication device, method and computer program product provide efficient average power tracking (APT) powering of transmit power amplifiers with fewer switching mode power supplies (SMPSs) to reduce size and cost of the communication device. A controller of the communication device detects an output voltage level of a battery supply of a communication device power amplifiers (PAs) assignable to respective transmit uplinks. The communication device includes a smaller second number of switching mode power supplies (SMPSs). The communication device includes linear regulator(s) that are powered by one of (i) output voltage of the battery supply and (ii) one of the one or more SMPSs. Controller selects a combination of SMPSs and linear regulators to power active PAs. The controller determines APT supply voltage value for each PAs and assigns the SMPS(s) and the linear regulator(s) to the PAs to achieve a highest overall or combined system power efficiency.

A controller having a wireless transmission interface is provided. The controller includes an amplifier, an analog-to-digital converter, a digital filter, a processor, and a radio frequency signal transceiver. The amplifier is coupled to the wireless transmission interface, and generates an amplification signal according to an input signal. The analog-to-digital converter is coupled to the amplifier, and configured to convert the amplification signal into a digital format. The digital filter is coupled to the analog-to-digital converter, and configured to filter the amplification signal in the digital format to generate a filtered signal. The processor is coupled to the digital filter, and configured to perform a calculation on the filtered signal to generate a calculation result. The radio frequency signal transceiver is coupled to the processor, and obtains received information according to the calculation result and the filtered signal.

The present invention is to generate a spatially phase modulated electron wave. A laser radiating apparatus, a spatial light phase modulator, and a photocathode are provided. The photocathode has a semiconductor film having an NEA film formed on a surface thereof, and a thickness of the semiconductor film is smaller than a value obtained by multiplying a coherent relaxation time of electrons in the semiconductor film by a moving speed of the electrons in the semiconductor film. According to the configuration, a spatial distribution of phase and a spatial distribution of intensity of spatial phase modulated light are transferred to an electron wave, and the electron wave emitted from an NEA film is modulated into the spatial distribution of phase and the spatial distribution of intensity of the light. Since the spatial distribution of phase of the light can be modulated as intended by a spatial phase modulation technique for light, it is possible to generate an electron wave having a spatial distribution of phase modulated as intended.

A power amplifier, for a transmitter circuit is disclosed, which comprises at least one field-effect transistor having a gate terminal and a bulk terminal. The at least one field-effect transistor is configured to receive an input voltage at the gate terminal and a dynamic bias voltage at the bulk terminal. The power amplifier comprises a bias-voltage generation circuit configured to generate the dynamic bias voltage as a nonlinear function of an envelope of input signal. The input voltage is a linear function of the input signal. The bias-voltage generation circuit comprises a rectifier circuit configured to generate a rectified input voltage and an amplifier circuit, operatively connected to the rectifier circuit, configured to generate the dynamic bias voltage based on the rectified input voltage. The amplifier circuit is a variable-gain amplifier circuit and the power amplifier comprises a control circuit configured to tune the gain of the amplifier circuit.

Envelope tracking schemes for Doherty power amplifiers are provided herein. In certain embodiments, an envelope tracking system includes a carrier amplifier that amplifies a first radio frequency signal, a peaking amplifier that amplifies a second radio frequency signal corresponding to a delayed version of the first radio frequency signal, an envelope tracker that generates a first power supply voltage that powers the carrier amplifier, and a delay circuit that delays the first power supply voltage to generate a second power supply voltage that powers the peaking amplifier. The envelope tracker controls a voltage level of the first power supply voltage to track an envelope of the first radio frequency signal. Thus, supply modulation is used to achieve gains in linearity, efficiency, and/or other performance metrics.

A method for compensating for degradation of a signal during transmission of the signal includes: performing thermal detection and accordingly generate a thermal detection result indicative of a temperature of a signal processing circuit; and performing property adjustment to adjust a predetermined property of the signal according to the thermal detection result. The property adjustment is performed on the signal according to the thermal detection result associated with previously transmitted signal. After performing the property adjustment, a characteristic value of the signal reaches a preset level.

A radio frequency front end circuit for a multimode transceiver has a first operating mode transmit input port, a second operating mode transmit input/receive output port, and a hybrid first and second operating mode receive output port. A first switch network has one or more switch elements together selectively connecting the first operating mode transmit input port, the second operating mode transmit input/receive output port, and the hybrid first and second operating mode receive output port to a coexistence filter first port. A second switch network has one or more switch elements that together selectively connect a coexistence filter second port to an antenna port.

An amplifier circuit includes: a plurality of amplifiers; a plurality of monitor elements provided for each of the plurality of amplifiers and disposed on a same chip with the corresponding amplifier; and a processor configured to: measure characteristics of each of the plurality of monitor elements; reduce a difference in distortion between a plurality of signals output from the plurality of amplifiers based on the measured characteristics; and compensate for the distortion.

An electronic device may include wireless circuitry with light sources, a set of photodiodes, a resonating element, and a common gate amplifier (CGA). In a transmit mode, the photodiodes may use optical local oscillators to generate equal portions of an antenna current amplified by the CGA for transmission by the resonating element. In a receive mode, the resonating element may generate an antenna current which is amplified by the amplifier and passed to the photodiodes. Including multiple photodiodes coupled to the amplifier in a current sharing configuration may serve to boost power. The amplifier may exhibit a wide bandwidth, may perform impedance matching between the resonating element and the photodiodes, and may isolate the photodiodes from antenna mismatch. The antenna may be integrated into a phased antenna array to further boost power.

Envelope tracking schemes for Doherty power amplifiers are provided herein. In certain embodiments, a mobile device includes a Doherty power amplifier that amplifies an RF signal for transmission on an antenna, and an envelope tracker that controls a supply voltage of the Doherty power amplifier based on an envelope of the RF signal amplified by the Doherty power amplifier. Thus, supply modulation is used to control the supply voltage of the Doherty power amplifier to achieve gains in linearity, efficiency, and/or other performance metrics. Furthermore, the Doherty power amplifiers herein can provide higher overall transmission efficiency and/or lower DC power consumption, which in turn leads to lower operating temperatures and/or improved reliability.