Modularized frequency synthesizing method based on direct digital and direct analogue combination

Abstract

The invention provides a modularized frequency synthesizing method based on direct digital and direct analogue combination, including the following steps: (1) direct digital frequency synthesizing method is adopted to generate M intermediate frequency marker signals with frequency interval of deltaF and bandwidth of (M-1)deltaF, namely F1, F1+deltaF, F1+2deltaF, ..., F1+(M-1)deltaF; (2) frequency shifting method is adopted to shift the frequencies of the M intermediate frequency marker signals generated in the step (1) to microwave frequency band, so as to generate M microwave local oscillation signals with frequency interval of deltaF and bandwidth of (M-1)deltaF, namely F2, F2+deltaF, F2+2deltaF, ..., F2+(M-1)deltaF; (3) indirect analogue frequency synthesizing method is adopted to generate N radio frequency marker signals with frequency interval of MdeltaF and bandwidth of (N-1)MdeltaF, namely F3, F3+MdeltaF, F3+2MdeltaF, ..., F3+(N-1)MdeltaF; (4) M microwave local oscillation signals generated in step (2) and N radio frequency marker signals generated in step (3) are subject to mixing, so as to obtain M*N frequency synthesis signals with frequency interval of deltaF and bandwidth of (MN-1)deltaF, namely F2+F3, F2+F3+deltaF, F2+F3+2deltaF, ..., F2+F3+(MN-1)deltaF, and the frequency synthesis signals are output. The invention realizes extremely rapid frequency conversion, extremely low phase noise and extremely low spurious level with low cost.

Description

technical field [0001] The invention belongs to the technical field of radar frequency synthesis, in particular to a modular frequency synthesis method based on the combination of direct digital frequency synthesis and direct analog. Applied in the design of radar frequency synthesizer, the performance of the frequency synthesizer can be greatly improved, and it is common to radar frequency synthesizers in various frequency bands, so that the hardware implementation circuit has good versatility and scalability. Background technique [0002] The frequency synthesizer is the heart of the modern electronic system and also the key component of the radar system, its quality directly affects the performance index of the radar system. [0003] Frequency synthesis is the combination of system components that generate one or more frequencies from one or several reference frequency sources. Frequency synthesis technology has a history of nearly 80 years. Early frequency synthesizers ...

AI Technical Summary

Problems solved by technology

[0008] The problem to be solved by the present invention is to provide a solution for the defects of the frequency conversion time, frequency resolution, phase noise, spurious level, bandwidth, volume and cost that exist in the above frequency synthesis methods. A new frequency synthesis method, so that the above indicators can be taken into account and further optimized, thereby greatly improving the performance of the entire frequency synthesizer

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