Microwave frequency estimation with high accuracy based on Mach-Zehnder Modulator and Phase Modulator

A technique for microwave frequency estimation with high accuracy based on Mach-Zehnder Modulator and Phase Modulator is proposed and demonstrated. In this proposed technique three dispersive fibers and two wavelengths are used to build power comparison factor. Wavelengths used are extracted from sidebands of MZM and then phase modulated with unknown frequency. Modulated signal is then passed through three stages of dispersive fiber followed by photo-diode. Received power from each photo-diode and its power comparison factors are utilized to estimate unknown frequency in the range of 2 - 20 GHz with maximum error of ±0.1GHz.