High Power Short Pulse Transmit/Receive Isolation Device

Transient radars for target detection and identification have the requirement of the equivalent of a T/R switch used in conventional narrowband radars. The requirements for mono and bi-static radars are somewhat different. We have identified 4-portdirectional coupler comprising of coupled TEM transmission lines and a protective switch as necessary and adequate hardware for both bi and mono-static systems. The proposed Phase-I effort will accomplish the required electromagnetic analysis for thedirectional coupler and the design, fabrication and preliminary testing of a prototype protective switch. As part of the protective switch development in Phase-I, we plan to have the ability in our experiments to investigate the performance of differentgasses, electrode materials and shapes. The switch recovery times become a critical parameter and will be the subject of our study in Phase-I. The development of the directional coupler will be the subject of Phase-II effort. The hardware developed inthis effort will be designed for pulse parameters of (100 kV to 500 kV), (100 ps to 250 ps) and (2 ns to 6 ns duration). This hardware can also be easily adapted for lower voltage (~ 10 kV) applications. Such hardware makes mono-static transient radarsystems possible which are assured of many industrial (e.g., detection of buried pipes etc)) and law-enforcement (e.g., seeing through walls) applications.