Microwave frequency measurement based on phase modulation to intensity modulation conversion using fiber bragg grating

摘要

A simple photonic technique for instantaneous microwave frequency measurement using an optical phase modulator and a fiber Bragg grating (FBG) is proposed and investigated. The FBG acts as tilt filters to offer different slopes of suppression for the optical carrier and the two sidebands when wavelengths are located at different positions of the FBG. A fixed relationship between the microwave frequencies and microwave powers is established. The microwave frequency can be estimated by measuring the microwave power differences. A measurement resolution of ±0.22 GHz over a 15 GHz measurement bandwidth is achieved. Experiments are performed to verify the effectiveness of the proposed approach.