1：Experimental Design and Method Selection:

The experiment utilized a wideband all-fiber frequency parametric comb with 25-GHz tone spacing for constructing a sub-GHz RF-photonic filter. The methodology involved phase and amplitude control of the comb tones and fourth-order dispersion compensation of the dispersive element.

2：Sample Selection and Data Sources:

A 25-GHz-pitched optical parametric comb seeded by a continuous wave (CW) laser at 1549.3 nm was used as the multi-wavelength source.

3：3 nm was used as the multi-wavelength source. List of Experimental Equipment and Materials:

3. List of Experimental Equipment and Materials: The setup included a commercial device Waveshaper 4000XS for pulse shaping, an erbium-doped fiber amplifier (EDFA), a dispersion compensating fiber (DCF) with a measured dispersion of -81.92 ps/nm at 1545 nm, and a photodiode with a 3dB bandwidth of 20 GHz.

4：92 ps/nm at 1545 nm, and a photodiode with a 3dB bandwidth of 20 GHz. Experimental Procedures and Operational Workflow:

4. Experimental Procedures and Operational Workflow: The comb lines were shaped in amplitude and phase using pulse shapers, amplified by an EDFA, and then passed through a DCF for dispersion compensation. The filter's performance was characterized using a Vector Network Analyzer (VNA) and tested with digital modulated RF signals.

5：Data Analysis Methods:

The filter transfer function was analyzed, and the integrity of the filter was verified by retrieving a set of digital modulated RF channels.