文件名称：2-Meter Vertical Dipole Array
文件大小：287KB
文件格式：PDF
更新时间：2022-03-07 10:33:44
天线列阵
Most commercial 2-meter repeater antennas with gain fall into two categories: collinear arrays and stacked element arrays, with gains ranging from 3 to 9 dB1. The higher gain antennas have a lower vertical beamwidth. For example, a typical 4-element exposed dipole offset array with 9 dB gain has a vertical beamwidth of 16°. This is the angle above and below the horizon at which the signal is half the strength (-3 dB) of the signal at the horizon. In general, high gain antennas work best from low level sites, or high elevation sites far away from the targeted area. For high sites near the target area, a lower gain antenna with a higher vertical beamwidth is used. This prevents the signal from passing over the target area