Microwave Photonic Channelizer With Large Instantaneous Bandwidth Based on AOFS

The microwave photonic channelizer can convert the RF signal into the optical domain for transmission and procession, effectively avoiding the limitation of electronic bottleneck, and realizing the instantaneous reception of ultra-wideband signal or multi-frequency signals, which can be perfectly applied to radar system and electronic warfare. In this paper, a microwave photonic channelizer based on dual-output image-reject mixer is proposed, both the signal path and the local oscillator path are divided into three paths by using an optical coupler. An acousto-optic frequency shifter (AOFS) is used by the optical local oscillator to shift the frequency to the left and right and then enters the image rejection mixer with the signal path. Finally, a 6 GHz bandwidth RF signal is divided into six subchannels with a bandwidth of 1 GHz to achieve simultaneous reception. This scheme needs no optical frequency comb and doubles the channelization efficiency, the image rejection ratio of the sub-channels is about 22 dB, and the spurious-free dynamic range of the system can reach 103.2 dB·Hz
^2/3
.