An optical AM video/PTZ data transceiver for a video-based surveillance network

Abstract

An optical amplitude modulation (AM) video/pantilt-zoom (PTZ) data transceiver for a short-range video-based surveillance network has been developed. It supports RS422 and RS485 formats for PTZ data transmission. In a receiver for an AM video signal, a DC-coupled automatic gain control (AGC) technique is used for a small size and low cost receiver. The fall time of the entire AGC process is approximately 2 seconds, and the AGC gain error varies by as much as ±2.8% for a 10 dB optic power range for the target transmission distance of around 10 to 20 km.