Cho, Jae-Hyoung Yook, Jong-Gwan Kim, Se-Yun 2024-01-19T12:09:41Z 2024-01-19T12:09:41Z 2022-03-07 2013 https://pubs.kist.re.kr/handle/201004/115430 A low power monostatic pulse borehole radar system is designed and tested for detecting a subversive intrusion tunnel with about 2 m diameter. According to our calculated budget under the condition that the transmitting signal is over 1 V peak with 10 ns full width half maximum, its switching speed becomes faster than 100 ns for detecting an air-filled tunnel nearby the employed borehole. To satisfy the above requirement, the monostatic pulse radar is fabricated with an active circulator using operational amplifiers and a switch for guaranteeing isolation and cutting off the direct signal. Then, the system performance is evaluated in a well suited tunnel test site. The measured data illustrate that the monostatic pulse radar provides the parabolic pattern of a typical tunnel signature comparable to that of a conventional bistatic pulse radar. English IEEE Low Power Monostatic Pulse Borehole Radar with an Active Circulator and an Absorptive Switch Conference 1 3rd Asia-Pacific Microwave Conference Proceedings (APMC), pp.570 - 572 3rd Asia-Pacific Microwave Conference Proceedings (APMC) 570 572 US Seoul, SOUTH KOREA 2013-11-05 2013 ASIA-PACIFIC MICROWAVE CONFERENCE PROCEEDINGS (APMC 2013) 000330851900185 2-s2.0-84893430639 Proceedings Paper