Microwave channelizer based on a photonic dual-output image-reject mixer

A microwave channelizer based on a photonic dual-output image-reject mixer (IRM) is proposed and demonstrated. By introducing the dual-output IRM based on the balanced Hartley structure, 2N channels can be produced by using the optical frequency combs (OFCs) with N comb lines. The required electrical hybrids and the optical filters are also reduced by half. In addition, the channelization efficiency is doubled, and the in-band interferences, including the image and the nonlinear mixing spurs, are greatly suppressed. A proof-of-concept experiment is performed. By applying a pair of OFCs with three comb lines, an RF signal with a 6 GHz instantaneous bandwidth is successfully divided into six channels with 1 GHz bandwidth. The in-band interference is suppressed by more than 25 dB for all channels.