Fig. 1. Schematic diagram of the microwave photonic system for wideband microwave frequency and phase noise measurement. LD: laser diode; PM: phase modulator; SMF: single-mode fiber; VODL: variable optical delay line; PolM: polarization modulator; SUT: signal under test; OBPF: optical bandpass filter; OC: optical coupler; Pol: polarizer; PD: photodiode; ADC: analog-to-digital converter; DSP: digital signal processing.

Fig. 2. Optical spectrum at the output of the PolM, the response of the OBPF, and the spectrum at the output of the OBPF.

Fig. 3. Frequency measurement of a 26.5 GHz signal. (a) Waveforms of the voltages at the output of the PDs; (b) phase term ψ(t,128ps/s); (c) estimated phase slope.

Fig. 4. Phase noise measurement results of the 26.5 GHz signal by the proposed system and a commercial phase noise analyzer, and noise floor of the proposed system and R&S FSWP50.

Fig. 5. (a) Frequency measurement and (b) phase noise measurement results of RF signals tuned from 5 to 50 GHz.