An integrated radio frequency terminal system includes an integrated modem configured to receive user data and communicate user data to and from a user device. The integrated modem includes a transmit tuner configured to receive the user data and convert the user data from baseband to an intermediate frequency band. The integrated modem includes a receive tuner connected to the baseband modem device and configured to convert received incoming data in the intermediate frequency band to baseband and provide the converted incoming data to the baseband modem device. The system includes a power amplifier connected to the integrated modem and configured to convert the user data from the intermediate frequency band to a radio frequency band. The system includes a low noise amplifier connected to the integrated modem and configured to convert received incoming data from the radio frequency band to the intermediate frequency band.

The present disclosure provides an apparatus that includes a first mixer circuit configured to convert between an RF signal and an IF signal based at least in part on an local oscillator (LO) signal. The first mixer circuit is electrically coupled to a first node that is configured to receive the LO signal and a first bias voltage, a second node that is configured to receive the RF signal or the IF signal, and a third node that is configured to provide the IF signal or the RF signal. The apparatus further includes a second mixer circuit electrically coupled to a fourth node configured to receive the LO signal and a second bias voltage, the second node, and the third node. The second bias voltage has a voltage level that is offset from the first bias voltage.

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.

A system for linearized-mixer interference mitigation includes first and second linearized frequency downconverters; a sampling analog interference filtering system that, in order to remove interference in the transmit band, filters the sampled BB transmit signal to generate a cleaned BB transmit signal; an analog interference canceller that transforms the cleaned BB transmit signal to a BB interference cancellation signal; and a first signal coupler that combines the BB interference cancellation signal and the BB receive signal in order to remove a first portion of receive-band interference.

A testing system includes: a bilinear polarized antenna for receiving and dividing a circularly polarized radio wave associating with a horizontal and a vertical polarization path of an object-to-be-tested into a first and a second high frequency signal; a phase retarder for delaying a phase of the first high frequency signal by 90 degrees to form a first high frequency signal with a phase delay of 90 degrees; a power splitter for receiving or synthesizing the first high frequency signal with the phase delay of 90 degrees and the second high frequency signal; and a high frequency signal transceiver for measuring power of the first high frequency signal with the phase delay of 90 degrees and the second high frequency signal and determining states of the horizontal and vertical polarization paths of the object-to-be-tested based on the power. Therefore, the testing system can speed up testing of the object-to-be-tested.

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.

An integrated circuit is disclosed. The integrated circuit includes a set of transceivers comprising a plurality of transceivers, all configured to transmit in the same transmit frequency band and receive in the same receive frequency band. Furthermore, the integrated circuit has a set of frequency synthesizers including a separate frequency synthesizer associated with each transceiver in the set of transceivers, wherein each frequency synthesizer in the set is configured to generate a local-oscillator (LO) signal to its associated transceiver. Moreover, the integrated circuit includes a control circuit configured to control the set of frequency synthesizers such that nearest neighbors in the set of frequency synthesizers generate LO signals at different frequencies (f.sub.1, f.sub.2, f.sub.3, f.sub.4).

A wireless communication device includes a first wireless communication system and a second wireless communication system. Regarding the first wireless communication system, an up-conversion circuit up-converts a first transmit (TX) signal in a baseband to generate a second TX signal with a first carrier frequency, and a front-end circuit transmits the second TX signal to another wireless communication device. Regarding the second wireless communication system, a first down-conversion circuit down-converts a first receive (RX) signal with a second carrier frequency to generate a second RX signal with a third carrier frequency, and a second down-conversion circuit down-converts the second RX signal with the third carrier frequency to generate a third RX signal in the baseband. The third carrier frequency is different from all fundamental frequencies included in a band combination that is employed at the first wireless communication system and is supported by another wireless communication device.

This application relates to the field of communications technologies, and in particular, to a digital predistortion processing method and apparatus. This application provides a digital predistortion processing method and apparatus. Digital predistortion processing of a multichannel power amplifier is supported through deprecoding processing by using one feedback link and one digital predistortion processor. In addition, after being amplified by a power amplifier, a precoded signal is fed back to the feedback link for predistortion parameter calculation, to improve quality of a transmit signal. The digital predistortion processing method and apparatus that are provided in embodiments of this application are intended to improve output linearity and efficiency of a multi-transmit-channel power amplifier while reducing implementation costs and complexity of a transmit device, and further improve overall system performance.

A wideband, linear, direct-digital RF modulator (DDRM) for a digitally-intensive transmitter (DTX) includes an interpolation filter and an in-phase/quadrature (I/Q)-interleaving RF digital-to-analog converter (RF-DAC). The interpolation filter suppresses sampling replicas in the DDRM's output RF spectrum. I/Q interleaving performed by the interleaving RF-DAC avoids problems associated with using two separate I- and Q-path RF-DACs. Each unit cell of the interleaving RF-DAC is capable of producing four unique non-overlapping waveforms covering all four quadrants of the I/Q signal plane. In one embodiment of the invention, the interleaving RF-DAC includes three parallel-connected RF-DACs operating in accordance with a multi-phase set of LO clocks to both cancel 3.sup.rd-order and 5.sup.th-order LO harmonics generated by the RF-DAC unit cells' interleaving logic and prevent 3.sup.rd-order intermodulation from occurring in the DTX's final stage RF power amplifier.