저잡음지역(3.5mV/m)의 AM방송송신 안테나 효율에 관한 연구

A Study on the efficiency of AM Broadcast Transmitting Antenna in assordance with a low noise Area

AM放送은 周波數(525~1605KHz)에 따라 放送區域(Service area)에 현저한 差異를 가져온다. 都市雜音이 增加됨에 따라 放送區域(Service area)이 縮小가 되고 있다. 따라서 送信出力을 增强하지 않은 한, 低雜音地域(3.5mV/m)에서 送信안테나의 效率을 增加시켜야 한다. 送信안테나 效率은 大地接地저항과 函數관계가 있다. 수직접지 안테나를 使用하고 있는 우리나라의 標準 AM 放送은 Radial ground System을 쓰고 있다.

The Service area in AM Broadcast Changes according to its transmitting frequency. It is also reduced by increase of the citizen noise. As a result, the efficency of transmitting Antenna should be higer in a low noise region as long as AM Broadcast does not build up its transmitting power. The efficiency of transmitting Antenna can also function as a low resistance connection to earth. Most Vertical Antenna used in the AM standard Broadcast band in the Korea have extensive radial ground systems beneath them which serve as image plane.