Embodiments of the present disclosure are directed to an antenna system and a mobile terminal. The antenna system includes a metal antenna, a radio frequency module, and an antenna tuning switch. The mobile terminal includes the antenna system mentioned above. An embodiment of the present disclosure is capable of improving the stability of sensor detection and prevent the whole machine from being in a state of power reduction for a long time, resulting in signal deterioration.

A radio frequency circuit includes an amplifier capable of amplifying a first radio frequency signal and a second radio frequency signal that has a frequency different from a frequency of the first radio frequency signal. Here, the amplifier uses a first power-supply voltage to amplify one of the first radio frequency signal and the second radio frequency signal and uses a second power-supply voltage to amplify both the first radio frequency signal and the second radio frequency signal together. A value of the second power-supply voltage is greater than a value of the first power-supply voltage.

Apparatuses and methods are disclosed regarding a multiband transmitter. In an example aspect, an apparatus for processing signals for wireless transmission includes a wireless interface device. The wireless interface device includes an upconverter, a tunable filter, and a driver amplifier. The upconverter has an output and is configured to upconvert a baseband frequency to a radio frequency based on a local oscillator signal. The tunable filter has an input and an output; the input of the tunable filter is coupled to the output of the upconverter. The driver amplifier has an input; the input of the driver amplifier is coupled to the output of the tunable filter.

A wireless signal processing circuit includes plural phase switchers, plural variable amplifiers and plural mixers. The plural phase switchers are provided on each of plural paths along which all in-phase signal and a quadrature signal are distributed. The plural phase switchers rotate the phases of the signals by signal phase rotation amounts according to a transmission direction of a transmission signal. The plural variable amplifiers alter amplitudes of input signals or output signals of the corresponding phase switchers in accordance with the transmission direction of the transmission signal. The plural mixers up-convert frequencies of the signals processed by the corresponding phase switchers and variable amplifiers.

A transmitter circuit includes at least one transmitting signal processing device, a compensation device and a compensation value calibration device. The at least one transmitting signal processing device sequentially generates multiple output signals according to multiple input signals. The compensation device sequentially generates the input signals according to multiple initial compensation values. The compensation value calibration device receives the output signals as multiple feedback signals and performs a calibration operation according to the feedback signals. The compensation value calibration device includes a digital signal processor coupled to the compensation device. In the calibration operation, the digital signal processor determines a first characteristic curve according to the initial compensation values and power of the feedback signals at a predetermined frequency, determines a first compensation value corresponding the minimum power according to the first characteristic curve and provides the first compensation value to the compensation device.

In certain aspects, a method includes receiving a first intermediate frequency (IF) signal and a second IF signal via a common input, upconverting the first IF signal into a first radio frequency (RF) signal, transmitting the first RF signal via a first antenna array, upconverting the second IF signal into a second RF signal, and transmitting the second RF signal via a second antenna array. In a first transit mode, the first RF signal is in a first frequency band and the second RF signal is in a second frequency band, and, in a second transmit mode, the first RF signal and the second RF signal are both in the first frequency band.

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.

An electronic modulating device is provided. The electronic modulating device includes a substrate, a plurality of first electrodes, a plurality of second electrodes, and a plurality of second electrodes. The plurality of first electrodes are disposed on the substrate. The plurality of second electrodes are disposed on the substrate. The common electrode is disposed opposite to the plurality of first electrodes and the plurality of second electrodes, and includes a plurality of openings. The electronic modulating device modulates an electromagnetic wave of radio frequency in a range from 1 G Hz to 100 T Hz.

A transceiver having a transceiver including a down-converter for converting a radio-frequency (RF) input signal to an intermediate frequency (IF) signal with an analog low latency bypass path coupled to the IF signal and configured to provide a low latency IF signal. There is a digital path coupled to the IF signal and configured to provide a digitally processed IF signal, and an up-converter for converting at least one of the low latency IF signal and the digitally processed IF signal to an RF output signal. In a further example, the down-converter and the up-converter convert to millimeter wave frequencies and filters the millimeter wave frequencies with cavity filters comprising quartz.

A direct digital synthesis transmitter that uses a programmable digital circuit to generate a digital signal representing at least one radio frequency signal, the generated signal is filtered, amplified by an amplifier, and provided to a transmission antenna without upconversion. The transmitter generating the digital signal at a desired output frequency range such that a frequency upconverter is not needed to produce signals in the desired radio frequency range.