A microwave photonic link with high spurious-free dynamic range based on a parallel structure

Abstract:

A microwave photonic link (MPL) with high spurious-free dynamic range (SFDR) is proposed and analyzed. The optical carrier is divided equally into two paths. The path 1 is modulated by radio frequency (RF) signals in a Mach-Zehnder modulator (MZM), and the phase of path 2 is controlled before the combination with path 1. By properly adjusting the phase difference of the two paths with the optical phase shifter, the third-order intermodulation distortion (IMD3) can be significantly suppressed. A proof-of-concept simulation is carried out. The results show that a reduction of 40 dB in the IMD3 and an improvement of 21.1 dB in the SFDR are achieved as compared with the conventional MZM-based MPL. The proposed MPL shows the advantages of simple structure, low cost and high efficiency.