Instantaneous microwave frequency measurement using optical carrier suppression based DC power monitoring

A novel photonic-assisted technique for instantaneous microwave frequency measurement is proposed using two cascaded Mach-Zehnder modulators (MZMs) biased at the transmission null point. Then, the microwave frequency can be estimated by monitoring direct current (DC) optical power. Moreover, the measurement range and the measurement resolution can be optimized by setting the time delay between optical and electrical link and optical dispersion, respectively. The approach is theoretically investigated and experimentally verified with a measurement range of 8 GHz and a measurement error of less than ± 0.15 GHz.