Image rejection mixer based on a bidirectional phase modulator with full-spectrum utilization. Issue 2 (19th January 2020)

• Record Type: Journal Article
• Authors: Chen, Dan; Shang, Tao; Li, Gufeng; Liu, Xiongchao; Zhang, Yinling
• Is Part Of: Journal of modern optics. Volume 67:Issue 2(2020)
• Page Start: 153
• Page End: 160
• Publication Date: 2020-01-19
• Subjects: Image rejection -- down-conversion -- microwave photonics -- phase modulator; Optics -- Periodicals; 535
• DOI: 10.1080/09500340.2019.1699970
• Languages: English
• ISSNs: 0950-0340

Abstract

ABSTRACT: An all-optical image rejection (IR) mixer, based on a dual electrical port phase modulation (PM) in a Sagnac loop and a wavelength division multiplexer (WDM), is proposed. The radio frequency (RF) and the local oscillator signals are loaded onto the two electrical ports of the PM, respectively. The two down-conversion channels are obtained with the use of WDM. A pair of phase orthogonal down-converted intermediate frequency (IF) signals are obtained by properly adjusting polarization controller. Then an electrical low-frequency 90 ∘ hybrid coupler (90 ∘ HC) combines the two IF signals to double the desired IF signal and suppress the image interference IF signal. In the simulation, a 30-GHz RF signal is successfully down-converted to 1 GHz with about 57 dB IR. Compared with the IR mixer based on two parallel PMs, conversion efficiency is improved about 6 dB.