八木天线由来及事理说明(国外英文资料).docVIP

八木天线由来及原理说明(国外英文资料) The name of the eight-wood antenna is not because it has eight antennas. By an active oscillator (general use or oscillator), a passive reflector, and a number of passive to implement parallel arrangement of the antenna, by the participants name. In the 20 s of the last century, tohoku university yagi show time and yutian too (two people invented the antenna, known as eight wooden yutian antenna, or yagi antenna. Eight wooden antennas do work well. It has a good direction and has a high gain from the dipole antenna. It is particularly good for measuring and communicating over long distances. If deserve to go up again the elevation and azimuth rotating control device, more can follow ones inclinations and all directions, including space vehicle radio contact, the feeling is not from the vertical antenna. A typical eight-wood antenna should have three pairs of vibrators, and the whole structure is king. The one that is connected to the feeder, or the main oscillator, is in the middle of the wang. A little longer than active oscillator said reflector, it in the side of the active vibrator, played a weakened waves coming from the direction or fired from the antenna to the radio; Slightly shorter than active vibration son quote to implement, it is at the other side of the active vibrator, it can enhance or coming from the side direction launch out in the direction of the waves. There can be a number of points, each of which is a little shorter than the one that is adjacent to it and near the active oscillator. Direction of director, the more sharp and gain higher and higher, but in fact more than four or five director, this is not too obvious increase in the benefits, and large size, increase the weight, improve on the material strength requirements, cost increase and other issues are increasingly prominent. Usually there is a five unit eight (that is, a reflector and an active oscillator). Every direction and reflector is made of a metal bar. No mat