Microwave Photonic Image-Reject Mixer with Improved Spurious-Free Dynamic Range

A dual-output microwave photonic image-reject mixer with improved spurious-free dynamic range (SFDR) is proposed and experimentally demonstrated. A single sideband (SSB) modulated optical signal is generated by using an electric hybrid (EH) and a dual-parallel Mach-Zehnder modulator (DP-MZM). Since the unwanted optical frequency components in the modulation process are suppressed, the third-order intermodulation distortion (IMD3) is effectively eliminated and the SFDR of the system is greatly improved. A confirmatory experiment is implemented. The suppression of the IMD3 components and the image-reject mixing is achieved simultaneously. The experimental results indicate that the fundamental component to IMD3 power ratio of 74 dB and the image-reject ratio (IRR) larger than 31 dB over 1-GHz bandwidth are realized. The SFDR of the proposed microwave photonic image-reject mixer is experimentally measured to be 112.7 dB.Hz
^2/3
, for which a 15-dB improvement is achieved.