Quadrature demodulator chip

Abstract

The invention provides a quadrature demodulator chip. The basic function of the quadrature demodulator chip is to realize signal frequency conversion. An input signal is a radio frequency signal, an output signal is a baseband signal, and down-conversion processing of the signal is realized by adding a local oscillator signal. The orthogonal signal generator adopts an SCL frequency divider to carry out frequency division on an input differential local oscillator signal and generates four paths of local oscillator signals with the same frequency and 90-degree phase difference, and the signals are amplified and buffered and are sent to the frequency mixer; the frequency mixer converts an input radio frequency signal into a current signal, the current signal and a local oscillator signal are mixed, and the current signal and the local oscillator signal are added in the resistive load and fed into the post-stage output buffer; the output buffer outputs the mixed IQ orthogonal signal, and realizes fixed impedance and broadband impedance matching through an on-chip resistor; the three parts are all provided with direct current bias through a bias module. Inputting a radio frequency signal differential form; the local oscillator signal is in a differential form or a single-ended form; the output baseband signal is an IQ orthogonal signal, and the frequency is the difference between the frequency of the local oscillator and the frequency of the radio frequency signal.

Description

technical field [0001] The invention belongs to the technical field of wireless communication transceiver systems, and in particular relates to an orthogonal demodulator chip. Background technique [0002] In modern communication systems, the extension of the frequency band and the extension of the transmission distance make the transmission process more and more popular in the radio frequency domain; and with the shrinking of the process size and the further improvement of computing power, signal processing must also be carried out in the digital domain. Although the performance of analog-to-digital converters and digital-to-analog converters is constantly improving, whether it is channel attenuation or transmission power requirements, a radio frequency front-end is required to achieve signal capture and transmission. As an indispensable part of wireless communication, the RF front-end can amplify and reduce the frequency of weak signals in its receiving part, and then prov...

AI Technical Summary

Problems solved by technology

[0004] The technical solution of the present invention is to propose a wide coverage, high linearity and low power consumption quadrature solution in response to the problems of low frequency band coverage and poor linearity of the quadrature demodulator encountered in the development of the RF front-end system of discrete components. tuner

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