Coherent wideband microwave channelizer based on dual optical frequency combs

摘要

Ultra-wideband Radio Frequency (RF) receiver is in great demand for military and civilian applications, such as radar system, electronic warfare, navigation and identification functions, however, the traditional analog-component-based receivers are vulnerable to electromagnetic interference (EMI) and are limited by their ability to cover broad spectrum [1]. Offering a large instantaneous bandwidth, photonic technology has been considered as a promising technique compared to pure electronic solutions. Many microwave photonic systems are being investigated to create large broadband RF receivers such as an optical filter based on multiple stages of optical ring lattices [2] used to slice spectrum and construct parallel channels and a wave scanning structure [3] to identify to-be-measured RF signals. However, in these schemes, the resolution and measurement speed are limited by external controlling signals. Recently, optical frequency comb (OFC) as a stable, accurate light source has been widely used in many high-performance signal processing and communication applications. A range of photonic channelizers based on OFC have been proposed and demonstrated [4-5]. Comparing with the conventional electronic methods, RF photonic channelizers make a breakthrough in analyzing of wideband RF spectral contents.