Design of S-Band Low Noise Block (LNB) for Radars with redundancy

This paper describes the Design & development of a Low Noise Block (LNB) with channel redundancy operating in S Band. In this module the input S band signal is down converted to IF frequency for further processing. It has two identical channels - Target Channel and Weather Channel. Each channel can be operated in two modes - High Beam (HB) mode and Low Beam (LB) mode, depending upon the target range. It provides a system gain of 39dB and a Noise Figure of 1.2dB (Max.). It is designed to operate in both continuous and pulsed mode.