Huawei Technologies Co., Limited

Min Yi

Nianyong Zhu

Wael Al-Qaq

Jian Liang

Zhihang Zhang

Xiaobao Yu

Liang Zhang

Meng Wang

Peng Gao

Weinan Li

Yusong Chi

Hongyu Wang

Zhuobiao He

Jianjun Zhou

Xinrong Hu

Yongchang Yu

Xinfang Liu

Bingxuan Mo

Wufeng Wang

This application provides an operational amplifier and a start-up circuit of the operational amplifier. The start-up circuit has the advantages of having a simple structure and consuming less. The operational amplifier includes a multi-stage amplifier and a start-up circuit, where the start-up circuit includes a first start-up transistor and a second start-up transistor. A source of the first start-up transistor and a source of the second start-up transistor are connected to a tail bias node of a first-stage amplifier in the multi-stage amplifier, a gate of the first start-up transistor and a gate of the second start-up transistor are configured to connect to a first bias voltage V, and a drain of the first start-up transistor and a drain of the second start-up transistor are connected to input terminals of a second-stage or higher-stage amplifier.

Operational amplifier and start-up circuit of operational amplifier

The present invention discloses a radio frequency receiver and a receiving method, where the method includes: performing band splitting on a radio frequency signal of multiple carriers to obtain at least one band signal, and outputting the signal; separately performing filtering and amplification processing on the at least one band signal to obtain at least one processed signal; generating multiple oscillation signals; and selectively receiving a processed signal, of the at least one processed signal, that includes a target carrier; receiving an oscillation signal corresponding to the target carrier; selectively selecting a frequency division ratio from multiple frequency division ratios; using the frequency division ratio to perform frequency division on the received oscillation signal to obtain a local oscillator signal; using the local oscillator signal to perform frequency mixing on the received processed signal that includes the target carrier to obtain a mixed signal.

Radio frequency receiver and receiving method

A circuit includes a polar transmitter to generate a radio frequency output from amplitude and phase signal components. The polar transmitter includes an amplifier to combine amplitude and phase signal components. A processor is coupled to the polar transmitter to provide the amplitude and phase signal components. The processor includes: a digital modulation circuit to generate a modulated digital signal including in-phase and quadrature signal components and a correction circuit to calculate and apply a complex digital offset for local oscillator feedthrough of the amplifier. The complex digital offset includes an in-phase offset correction factor and a quadrature offset correction factor.

Polar transmitter with feedthrough compensation

A radio frequency transmitter includes a digital-to-analog converter, an analog baseband processor, and a modulator. The digital-to-analog converter is configured to convert a digital frequency-converted signal into a first analog signal, where the digital frequency-converted signal is obtained by performing digital frequency conversion on a digital baseband signal based on a first frequency signal; the analog baseband processor is configured to perform filtering and gain adjustment on the first analog signal to obtain a second analog signal; and the modulator is configured to perform up conversion based on a second frequency signal and the second analog signal, to obtain a radio frequency signal, where the second frequency signal is determined based on a local frequency signal and the first frequency signal.

Radio frequency transmitter and signal processing method

The present invention relates to a modulation circuit of a digital transmitter, a digital transmitter, and a signal modulation method. The modulation circuit includes: a first synchronizing circuit and a digital modulator, where the first synchronizing circuit separately perform phase delay on a first local-frequency signal or a second local-frequency signal to obtain corresponding delay signals, and perform phase adjustment on a digital baseband signal by using the delay signals, to generate a first adjusted signal and a second adjusted signal; and the digital modulator modulates the first adjusted signal by using the first local-frequency signal, to generate a first radio-frequency signal, and modulates the second adjusted signal by using the second local-frequency signal, to generate a second radio-frequency signal.

Modulation circuit of digital transmitter, digital transmitter, and signal modulation method

An equivalent radio frequency (RF) notch filter, an RF chip, and a receiver are provided. The equivalent RF notch filter includes: a local oscillation (LO) circuit, configured to provide a LO frequency signal; configured to be connected in parallel with the main chain, and down-convert signals of the main chain; and a frequency selective circuit realized by impedance difference, configured to provide different impedances for down-converted signals with different frequencies from the mixing circuit, so as to absorb the signals that need to be suppressed.

Equivalent radio frequency notch filter, radio frequency chip, and receiver

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Shanghai, China

Min Yi