Stable Remote Receiving System with Different Down-conversion Methods

We present a time-stable remote receiving system for X-band radar signals. The transmission delay variation of the broadband signal is compensated for at the local end with a synchronized sample clock. The X-band signal is down-converted with three distinct methods at the electrical or optical domain. Experimentally, a root mean square (RMS) timing jitter of less than 10 ps is achieved for the radar signal after 25 km fiber transmission. This comparison provides insights and guidance for the design of remote ends for a multi-antenna distributed receiving system.