A Frequency Source Circuit of Harmonic Generation and Mixing

Abstract

The invention discloses a frequency source circuit with harmonic generation and frequency mixing. The frequency source circuit comprises a crystal oscillator, a digital phase discriminator, a first filter, a second filter, a loop filter, a first amplifier, a second amplifier, a harmonic generator, a voltage-controlled oscillator and a frequency mixer. According to the frequency source circuit, the frequency mixer and a harmonic generation circuit are added in the conventional single loop digital frequency source circuit, a different signal after frequency mixing is controlled within 200 MHz, when the different signal is fed back to the digital phase discriminator, a frequency dividing ratio of the digital phase discriminator is reduced, when the output frequency of the voltage-controlled oscillator is multiple times smaller than the oscillation frequency of the crystal oscillator, a phase noise index is optimized. In comparison with the conventional single loop digital phase lock circuit, phase noise and spurious performance are improved; in comparison with the conventional single loop sampling phase lock circuit, debugging is unnecessary and the frequency precision is high. Through reasonable layout design, all circuits can provide local frequency source signals for satellite-borne receivers and transmitters.

Description

technical field [0001] The invention relates to a frequency source circuit for harmonic generation and frequency mixing, which belongs to the technical field of microwave circuits. Background technique [0002] With the continuous development of satellite technology, the spaceborne frequency source often needs to achieve the output frequency of the voltage controlled oscillator as a fractional multiple of the crystal oscillator's own oscillation frequency. At the same time, the phase noise index and spurious index of this frequency source are put forward higher requirements. In order to meet the design requirements of a certain type of spaceborne frequency source, the related frequency source design is carried out. [0003] The frequency source is widely used in various satellite communication systems, and its performance directly affects the performance of the entire satellite communication system. The traditional single-loop digital phase-locked frequency source circuit ...

AI Technical Summary

Problems solved by technology

[0004] Technical problem solving of the present invention: overcome the deficiencies in the prior art, propose a kind of frequency source circuit that harmonic generation adds frequency mixing, by adding harmonic generator, mixer, The amplifier and filter have improved the spurious index and phase noise index of the frequency source circuit very well, and solved the problems that the existing spaceborne frequency source cannot be multiplied by decimals, the phase noise is poor, the spurious suppression is poor, and the debugging is difficult.

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