Microwave Photonics Time-Delayed Mixer

In this paper, an efficient photonics time-delayed mixer (PTDM) is proposed and demonstrated. It mainly consists of a dual-parallel Mach-Zehnder modulator (DPMZM) and a dispersion medium (DM). To eliminate the carrier component, the carrier-suppressed dual-sideband (CS-DSB) modulation is implemented without optical filters. Besides, the CS-DSB modulation is also the key to make the phase response is proportional to the converted frequency. Thanks to the controllable DC bias of the modulator, the power response of this PTDM is also tunable. Thus, this property also endows the PTDM able to resist the dispersion-induced power fading (DIPF) when considering the use of large dispersion medium. Experimental results verify the ability of wideband frequency up- and down-conversion. Moreover, a converted signal with linear phase-frequency response is also achieved, which implies the time delay capability. Time delay tuning is realized by altering the wavelength of the carrier with a stable power response. This structure is very compact and thus compresses the signal processing system volume, which is qualified to be integrated into a receiver/transmitter.