A device and method for synthesizing broadband microwave signals with low phase noise

Abstract

The invention discloses a broadband microwave signal low-phase noise synthesizing device and method. The device comprises a reference source, a fractional frequency division oscillating circuit, a broadband sampling local oscillating circuit, a sampling frequency mixer, a middle-frequency filter, a phase discriminator, a circuit integrator, a broadband microwave oscillator, a broadband microwave amplifier, an amplifier, a frequency multiplier, a narrowband filter, a high-purity-point frequency synthesizing circuit, a band-pass filter, a broadband filter, a broadband microwave frequency mixer and a low-pass filter. According to the broadband microwave signal low-phase noise synthesizing device and method, the broadband microwave signal low-noise synthesis technology according to which fixed frequency mixing, sampling and frequency mixing are combined, a traditional broadband sampling procedure is improved, namely before sampling on a feedback signal is carried out by a YIG oscillator, the feedback signal is mixed with a highly-pure local oscillation signal with the fixed frequency at first and the frequency of a local oscillation signal is converted from a high frequency into a low frequency. Then the local oscillation signal enters a sampler and undergoes sampling and frequency mixing with a sampling local oscillation signal. Thus, the sampling harmonic number can be reduced, and therefore deterioration of phase noise is relieved.

Description

technical field [0001] The invention relates to a device for synthesizing broadband microwave signals with low phase noise and a method for synthesizing broadband microwave signals with low phase noise. Background technique [0002] In the traditional broadband microwave signal low-noise synthesis circuit, a multi-phase-locked loop structure is usually used, combined with figure 1 , which includes a reference source circuit, an integer or fractional frequency division circuit, a broadband sampling oscillator circuit, a sampling mixing circuit, an intermediate frequency filter, a phase detector, a loop integrator, a broadband microwave oscillator, and a broadband microwave amplifier. in: [0003] The reference source circuit generates the reference signal required by the fractional frequency division oscillator circuit and the broadband sample oscillator circuit. [0004] The fractional frequency division oscillating circuit generates the phase detection reference signal re...

AI Technical Summary

Problems solved by technology

Therefore, subject to the F S It is very difficult to further improve the phase noise index of the broadband microwave signal F based on the influence of the phase noise of the sampling signal oscillator signal

[0014] The near-carrier phase noise of the broadband low-noise frequency synthesis method commonly used at present is severely limited by the phase noise of the sampled oscillator signal, which restricts the further improvement of the phase noise index of the synthesized broadband microwave signal

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