A transmitter includes a plurality of transmitter circuits configured to generate signals that are within the same frequency band; and a feedback circuit that is shared by the plurality of transmitter circuits, the feedback circuit being configured to feed back a part of a transmission amplification signal to a transmitter circuit, the transmission amplification signal being output from each of the plurality of transmitter circuits through a transmission amplifier, and the transmitter circuit being configured to output the transmission amplification signal among the plurality of transmitter circuits. The feedback circuit includes a frequency selective extraction unit configured to extract different-band signals in frequency bands from the transmission amplification signal, the frequency bands being different from each other, a synthesis unit configured to synthesize the different-band signals extracted by the frequency selective extraction unit, and to generate a synthesis signal, a frequency conversion unit configured to frequency-convert the synthesis signal generated by the synthesis unit by using a local signal of the same frequency, the local signal being common to a plurality of transmission paths, and a distortion compensation coefficient calculation unit configured to calculate a distortion compensation coefficient based on signals of frequency bands of the different-band signals, the distortion compensation coefficient being used when compensating for distortion of signals in outputs of the plurality of transmitter circuits.

In accordance with various embodiments of the disclosed subject matter, a system, apparatus and method is configured to provide a poly-phased, time-interleaved radio frequency (RF) digital-to-analog converter (DAC) suitable for use in radar, radio, mobile and other RF systems.

In accordance with various embodiments of the disclosed subject matter, a system, apparatus and method is configured to provide a poly-phased, time-interleaved radio frequency (RF) digital-to-analog converter (DAC) suitable for use in radar, radio, mobile and other RF systems.

An electronic modulating device is provided. The electronic modulating device includes a substrate, a plurality of first modulating electrodes disposed on the substrate, and a plurality of second modulating electrodes disposed on the substrate. The area of one of the first modulating electrodes is greater than the area of one of the second modulating electrodes. The ratio of the number of first modulating electrodes to the number of second modulating electrodes is in a range from 0.5 to 2.0.

Operating in a low frequency band and a high frequency band, the device includes at least a first amplification module capable of operating in the high band, the amplification of which is modulated according to a tracking of the envelope of the input signal of the device, capable of being linked at the output to an antenna adapted to the high band; a second amplification module capable of operating in the low band and of performing the envelope tracking; a switch switching the output of the second amplification module to an antenna adapted to the low band, when the amplification device is operating in the low band; to the first amplification module to control the drain voltage of the first module according to the envelope tracking, when the amplification device is operating in the high band.

Operating in a low frequency band and a high frequency band, the device includes at least a first amplification module capable of operating in the high band, the amplification of which is modulated according to a tracking of the envelope of the input signal of the device, capable of being linked at the output to an antenna adapted to the high band; a second amplification module capable of operating in the low band and of performing the envelope tracking; a switch switching the output of the second amplification module to an antenna adapted to the low band, when the amplification device is operating in the low band; to the first amplification module to control the drain voltage of the first module according to the envelope tracking, when the amplification device is operating in the high band.

According to an aspect, there is provided a method for power-amplification of a transmission signal, comprising: obtaining the transmission signal with phase and amplitude modulation; generating a power-amplified polar signal for approximating a power-amplified transmission signal by power-amplifying a first constant-envelope signal with one of two or more first amplification factors based on the transmission signal; generating an outphasing) pair of a first power-amplified outphasing signal and a second power-amplified outphasing signal based on the transmission signal; and combining the power-amplified polar signal, the first power-amplified outphasing signal and the second power-amplified outphasing signal to provide the power-amplified transmission signal.

High efficiency amplitude DACs (Digital-to-Analog Converters) and RFDACs (Radio Frequency DACs) employing such amplitude DACs are discussed. One exemplary embodiment is a DAC comprising a plurality of DAC stages, wherein each DAC stage of the plurality of DAC stages is associated with a respective predetermined voltage of a plurality of predetermined voltages, wherein each DAC stage of the plurality of DAC stages can receive a digital signal at the respective predetermined voltage associated with that DAC stage when the respective predetermined voltage of that DAC stage is a selected predetermined voltage, wherein the selected predetermined voltage is based on an amplitude of the digital signal, and wherein each DAC stage of the plurality of DAC stages can generate a respective analog signal associated with that DAC stage based on the digital signal received at that DAC stage when the respective predetermined voltage of that DAC stage is the selected predetermined voltage.

In a modulation correction method, an adjusted amplitude is determined based on an amplitude between adjacent zero crossings of a modulated signal, the adjacent zero crossings are shifted to determine shifted zero crossings, and the modulated signal is adapted based on the adjusted amplitude and the shifted zero crossings to generate a corrected modulated signal corresponding to the modulated signal.

The disclosed embodiments relate to the design of a system that implements an up-conversion mixer. This system includes a regulator-based linearized transconductance (g.sub.m) stage, which converts a differential intermediate frequency (IF) voltage signal into a corresponding pair of IF currents. It also includes a pair of current mirrors, which duplicates the pair of IF currents into sources of a set of switching transistors. The set of switching transistors uses a differential local oscillator (LO) signal to gate the duplicated pair of IF currents to produce a differential radio frequency (RF) output signal. Finally, a combination of capacitors and/or inductors is coupled to common source nodes of the set of switching transistors to suppress higher order harmonics in an associated common source node voltage signal.