Wideband Microwave Frequency Measurement Based on Unbalanced Stimulated Brillouin Scattering

We report a wideband microwave frequency measurement approach with high precision based on unbalanced stimulated Brillouin scattering (SBS). Two unbalanced Brillouin gain spectrums (BGS) generated by single-sideband modulation are utilized to locate the unknown frequency unambiguously. The proposed scheme is theoretically analyzed and experimentally verified. Experimentally, microwave signals in a wide frequency range from 0 to ∼33 GHz (three times Brillouin frequency shift) are precisely measured with errors of less than ±2 MHz only using a low frequency microwave source.