Proceedings of the Korean Institute of Information and Commucation Sciences Conference (한국정보통신학회:학술대회논문집)
- 1999.05a
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- Pages.254-260
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- 1999
Improvement of duty rate of Meteor Burst communication with Buried Antenna
매설형 안테나를 이용한 유성 버스트 통신의 도통율 개선
Abstract
Meteor Burst Communication can provide effective and economical means of communication where long distance VHF NLOS data transmission is needed; often ranges more than 1000 km. It has been, however, so far considered unsuitable for short distance application because of phenomenal decrease in burst durations, which leads to decreation of total duty rate of the system. This paper extensively analyzes characteristics of shot distance MB(Meteor Burst) path and shows the low duty rate may be improved by increasing burst rate through adapting antenna beam width to cover entire hot-spot region in the space and, by compensating effective burst length through cutting down man-made noises introduced by antenna. Based on the analysis, we are developed a small-opening-cavity antenna, especially designed for short distance MB path. In operation, the antenna is to be buried under ground surface so as to improve directivity and reduces noise introduction. The antenna exhibits power gain of 3 dB with 90 degree beam width and thus enables to illuminate entire hot-spot regions with the elevation angle of 8-90 degree which is the case of transmission less than 100 km. Directivity horizontal to earth surface is suppressed to minimum which enables to cut man-made noises from near-by sources down to more than 3 dB from the level reported with conventional 4 element Yagi. A series of experiments performed on 100 km MB paths have conformed that, with the antenna installed at receiving site, the burst rate and duration time have been noticed to increase by 10 and 20 percent respectively from the values obtained by conventional 4-element Yagi antenna under same testing condition.
유성버스트 통신방식은 1000 km 이상의 장거리 VHF NLOS 데이터 통신 시스템을 가장 경제적인 방법으로 구현 시켜줄 수가 있다. 그러나 이 방식은 도통율이 열화 함으로 본질적으로 실용에는 부적합한 것으로 알려져 있다. 송, 수신안테나의 빔 패턴이 공간의 hot-spot을 완전히 포용할 수 있도록 함으로서 버스트의 발생빈도를 증가시키는 동시에 안테나에 유도하는 지상 잡음 전계를 효과적으로 차단함으로서 수신기의 실효 차단전압을 낮추어 시스템의 도통율(duty rate)을 개선 할수 있다. 소개구형 공동형 안테나를 개발하였다. 이 안테나는 지하에 매설하여 사용하는데 이렇게 함으로서 수직방향의 지향성이 개선되고 지상으로부터의 잡음 혼입이 효과적으로 차단된다. 이 안테나는 3dB 빔 폭이 90
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