Fig. 1. (a) High frequency microwave signal generator; (b) Test scene diagram

Fig. 2. (a) Homodyne detection spectrum of ring-1; (b) Homodyne detection spectrum of cascade optical fiber ring; (c) Homodyne detection spectrum of Cascade optical fiber ring and Sagnac ring

Fig. 3. Spectrum of dual-wavelength laser signal output

Fig. 4. High frequency microwave signal output spectrum

Fig. 5. Frequency drift and power changes of high frequency microwave signals

Fig. 6. Line width fitting of high frequency microwave signal

Fig. 7. Tuning range of high frequency microwave signal