An apparatus is disclosed that includes a transmit chain, a duplexer, a receive chain and a control circuit. The transmit chain is configured to generate a transmit signal at a transmit frequency. The duplexer is configured to pass the transmit signal to an antenna that generates a transmit leakage current into a received signal. The receive chain is configured to obtain the received signal and measure the leakage current from the transmit chain. The control circuit is configured to determine reduced performance parameters for the transmit chain based on the determined leakage signal, wherein the transmit leakage signal is inversely proportional to the reduced performance parameters.

The present disclosure provides a radio unit with internal parallel antenna calibration. The radio unit comprises an antenna calibrator, a plurality of transmission signal processing sections, a plurality of power amplifiers, a plurality of bandpass filters, a plurality of couplers, a plurality of reception signal processing sections and a first combiner. The antenna calibrator is configured to generate a plurality of individually identifiable reference signals used for transmission calibration. The transmission signal processing sections are configured to modulate the signals in parallel. The power amplifiers are configured to amplify the modulated signals to predetermined power levels in parallel. The bandpass filters are configured to apply bandpass filtering operations to the modulated signals in parallel. The couplers are configured to couple the filtered signals to a first combiner, which combines the filtered signals. One of the reception signal processing sections is configured to identify and demodulate each of the filtered signals constituting the combined signals. The antenna calibrator is further configured to compute transmission calibration vectors by comparing the demodulated signals with the reference signals.

Provided is a transmitter which can maximize the efficiency of rectification in a power-receiving electronic device irrespective of the distance therebetween. The transmitter transmits electric power to the electronic device through use of a microwave. The electronic device receives the microwave, converts the microwave to DC power, and uses the DC power as operation power. The transmitter includes a carrier wave generator for generating a carrier wave; a modulating signal generator for generating a modulating signal whose level increases, decreases, or increases and then decreases during one cycle; an amplitude modulator for amplitude-modulating the carrier wave generated by the carrier wave generator by, the modulating signal output from the modulating signal generator and for amplifying the modulated carrier wave and outputting the amplified, modulated carrier wave as a transmission signal; and an antenna for radiating the transmission signal output from the amplitude modulator into a space as the microwave.

A transmission power control method and an electronic device capable of adjusting a bias of a power amplifier are provided. The electronic device includes: a temperature sensor; a power amplifier (PA); and a controller configured to monitor signals from the temperature sensor, determine a bias value for the PA, based on the monitored signals, and control the PA to amplify a signal for transmission based on the determined bias value.

An I/Q imbalance calibration method includes sequentially inputting a first in-phase and quadrature signals calibration signal to a front-end circuit of the transmitter system to acquire and estimate a first and second calibration signal strengths sequentially, wherein a delta estimation is adopted; calculating an I/Q gain imbalance according to estimated first and second calibration signal strengths; sequentially inputting a second in-phase calibration signal and both of the second in-phase and quadrature calibration signal to the front-end circuit of the transmitter system to acquire and estimate a third and fourth calibration signal strengths sequentially, wherein an I/Q gain imbalance compensation is formed on the first in-phase and quadrature calibration signals to generate the second in-phase and quadrature calibration signals; and calculating an I/Q phase imbalance according to estimated third and fourth calibration signal strengths.

A circuit includes a first device between a first input node and an internal node, a second device between a second input node and the internal node, a third device between the internal node and ground, a fourth device between the internal node and an output node, and a fifth device between the output node and ground. The second and third devices generate a direct current (DC) voltage on the internal node by dividing a bias voltage on the second input node. The fourth device generates, from the DC voltage, a first component of an output voltage on the output node. The first and third devices generate a modulation signal on the internal node by dividing a radio frequency (RF) signal on the first input node. The fifth device rectifies the modulation signal to generate a second output voltage component.

A technique for determining a time alignment (TA) error in a circuitry is provided. One or few measurement cycles can be utilized for a closed-loop TA alignment, e.g., for envelope tracking in a transmitter. As to a method aspect of the technique, the amplitudes of a first signal and a second signal are determined. A first measure is computed that is indicative of a relative amplitude error, and a second measure is computed that is indicative of a variation of at least one of the amplitudes. The TA error is determined by correlating the first and second measures.

Transmission and reception of communications via high frequency antenna systems employing cooled pure copper or high-temperature superconductor filters and/or amplifiers are presented. A comb linear amplifier combiner and comb limiter combiner may be modified with, for example, cryogenically cooled pure copper and/or high-temperature superconductor components, such as matching units of bandpass filters. A computer control unit may be coupled to the transmission circuit and reception circuit to control operation of one or more filters, and/or amplifiers.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for providing a user with feedback regarding power consumption in a battery-operated electronic device. In one aspect, a method performed by data processing apparatus includes identifying, using the data processing apparatus, usage of a hardware component of a battery-operated electronic device that includes the data processing apparatus, attributing the usage of the hardware component to the hardware component or to a software application that uses the hardware component, recording, using the data processing apparatus, a power consumption resulting from the usage, and presenting power consumption feedback to a user using the data processing apparatus. The power consumption feedback identifies the hardware component or the software application of the electronic device and the power consumption resulting from the usage.

A power detector is described herein that detects a true power provided by power amplifier of an RF transmitter. The power detector may include a plurality of voltage detectors that determine one or more voltages of a power amplifier included in the RF transmitter and/or a transformer included in the RF transmitter. At least one of the voltage detectors may be coupled to a sense inductor that senses one or more magnetic fields emitted by the transformer. The at least one voltage detector coupled to the sense inductor determines the voltage induced across the sense inductor as a result of the sensed magnetic field(s). The determined voltage(s) may be used to determine the load impedance of an antenna of the RF transmitter that transmits the RF signals. The load impedance may be used to accurately measure the power regardless of any impedance mismatches between the power amplifier and the antenna.