Low-noise microwave synthesizer that uses the tuning for high frequency comb drift cancellation loop

摘要

Microwave synthesizer according to the present invention comprises a narrow-band input, a low-frequency comb input, a wide-band input, a drift cancellation loop and an output for providing an output signal of adjustable frequency. Narrow-band synthesizer is coupled to the narrow band input, comb generator is coupled to the low-frequency com input. Topology conventional as has been done, instead of using a broadband synthesizer to drive the wide-band input, the present invention uses a high stability, a high-frequency low-noise oscillator. The oscillator output is mixed with the output of the comb generator, a high-frequency comb low noise is generated. Then, by using a high-frequency comb of the low noise, wide band input of the drift cancellation loop is driven. Compared to conventional designs, it is possible to obtain a significant reduction in phase noise.