Abstract:

It is difficult for the traditional analog comb generator to achieve high flatness, small frequency spacing and flexible adjustment. This study proposed a new way to realize comb signal based on phase-locked loop mechanism. Specifically, the output of the N divider in the phase-locked loop feedback branch generated a pulse signal with a narrow pulse width by dividing high frequency signal of the voltage-controlled oscillator. The pulse passed through the filter to obtain a high-flatness comb signal that satisfies the target bandwidth. By flexible programming control of the divider, the comb signal with different frequency spacing was obtained without modifying the hardware circuit design. The experimental results showed that the spectral line generated by the comb spectrum generator based on PLL had the advantages of large signal bandwidth, high amplitude uniformity, adjustable frequency spacing, miniaturization and low power consumption.

Key words: comb generator, phase locked loop, large signal bandwidth, high amplitude uniformity, adjustable frequency spacing, miniaturization and low power consumption