Ultra-wide Microwave Frequency Down-Conversion Based on Cascaded Four-Wave Mixing

A photonic-assisted method is proposed for microwave frequency down-conversion based on four-wave mixing with a low-frequency electrical local oscillator (LO). A tunable and ultra-wide optical LO is achieved based on cascaded FWM (CFWM) and re-circulating FWM (RFWM), which is successfully demonstrated in the microwave frequency conversion for the RF range of 5–40 GHz down-converted to IF band below 2 GHz with a low-frequency electrical LO below 5 GHz.