A frequency mixer and frequency mixing method

Abstract

The invention discloses a frequency synthesizer and a frequency synthesis method. The frequency synthesizer comprises: a large-stepping phase lock loop and a direct digital frequency synthesizer, an orthogonal mixer and a tracking phase lock loop. The orthogonal mixer is connected with the large-stepping phase lock loop and the digital frequency synthesizer respectively for mixing the frequency generated by the large-stepping phase lock loop and the low frequency generated by the direct digital frequency synthesizer to generate a single-sideband single tone; the tracking phase lock loop is connected with the orthogonal mixer for receiving the single-sideband single tone output by the orthogonal mixer and filtering the sideband leakage and oscillation leakage of the signal. The invention provides a frequency synthesizer with wide band width, small stepping, low stray and low noise and a frequency synthesis method. The invention has simple hardware structure and is easy to accomplish.

Description

technical field [0001] The invention relates to the technical field of wireless communication, in particular to a frequency synthesizer and a frequency synthesis method in a radio frequency transceiver. Background technique [0002] Due to the rapid development of wireless communication technology in recent years, more and more attention has been paid to the design and research of integrated circuits in related fields. A frequency synthesizer is used to generate a local oscillator signal and is the most important module in the front end of a radio frequency transceiver. At present, the schemes for realizing small-step frequency synthesizers all use phase-locked loop (PLL). Phase-locked loop (PLL) is an automatic control circuit for the purpose of eliminating frequency error. An error, specifically, is a circuit that synchronizes an output signal (produced by an oscillator) with a reference or input signal in frequency and phase. A phase-locked loop is generally composed of...

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Problems solved by technology

Especially in the case of broadband and small steps, these two indicators are more difficult to achieve

There is a frequency synthesizer that can achieve broadband, low spurious, and small step performance. The implementation method is to a

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