We propose and demonstrate a photonic approach to instantaneous frequency measurement with an extended range based on phase modulation. In the measurement system, two optical wavelengths and two dispersion fiber segments are used to construct the frequency-dependent amplitude comparison functions (ACFs). Several ACFs can be utilized jointly to determine the microwave frequency without ambiguities beyond a monotonic region of the lone conventional ACF. The measurable range of microwave frequency can be extended and the accuracy can be improved by selecting an ACF with a large slope. The experimental results show that the errors are limited within ±140 MHz of a frequency measuremental range from 8 to 20 GHz.
© 2013 Chinese Optics Letters
(060.0060) Fiber optics and optical communications : Fiber optics and optical communications
(060.5060) Fiber optics and optical communications : Phase modulation
(060.5625) Fiber optics and optical communications : Radio frequency photonics
Fiber Optics and Optical Communications
Xiuyou Han, Siteng Zhang, Chao Tong, Nuannuan Shi, Yiying Gu, and Mingshan Zhao, "Photonic approach to microwave frequency measurement with extended range based on phase modulation," Chin. Opt. Lett. 11, 050604- (2013)