Frequency synthesizer

Abstract

The invention relates to a frequency synthesizer. The frequency synthesizer comprises a phase-locked loop module, a loop filter and a voltage controlled oscillator module, wherein the voltage controlled oscillator module includes a multistage voltage controlled oscillation unit; the voltage controlled oscillation unit comprises resonance circuits and switching control circuits, wherein the resonance circuits and the switching control circuits are electrically connected and are composed of multiple separate electronic components; and resonance parameters of each of the resonance circuits are different, thereby generating resonance frequencies for resonating different frequency ranges. Through the multistage voltage controlled oscillation unit composed of the multiple separate electronic components, the cost is low, the resonance parameters in the resonance circuits further can be adjusted, and the signals having different frequency bands are output; and through the multistage voltage controlled oscillation unit, the frequency synthesis with non-overlapped stage frequency ranges and seamless connection is realized, and the phase noise of the output signals of the frequency synthesis is further reduced.

Description

technical field [0001] The present invention relates to frequency synthesis technology, in particular to frequency synthesizer. Background technique [0002] Frequency synthesis technology is one of the key technologies for radar, communication and other electronic systems to achieve high performance indicators. Since the phase noise of the frequency synthesizer will affect many indicators of the receiving and transmitting systems, such as the adjacent channel selectivity of receiving, Transmitted adjacent channel power ratio, etc. When the receiving and transmitting frequency bands are very wide, the phase noise of the frequency synthesis part generally deteriorates sharply, and this deterioration is mainly caused by a voltage-controlled oscillator (Voltage Controlled Oscillator, VCO). [0003] For the voltage-controlled oscillators of the wide-band receiving and transmitting local oscillators, a single wide-band integrated voltage-controlled oscillator chip provided by fo...

AI Technical Summary

Problems solved by technology

[0003] For the voltage-controlled oscillators of the wide-band receiving and transmitting local oscillators, a single wide-band integrated voltage-controlled oscillator chip provided by foreign RF IC manufacturers is mainly used or multiple narrow-band dedicated integrated voltage-controlled oscillators are used for synthetic design, but this The price of the two integrated voltage-controlled oscillators is expensive, generally costing hundreds of dollars or even thousands of dollars, and the output frequency of the voltage-controlled oscillator is not adjustable

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