在散射条件下对电磁极化技术的实验研究

Experimental study of the electromagnetic polarization technique in a scattering environment

由于在散射环境中存在比自由空间多2倍的极化独立空间信道,故在被给定的点下有6个可区别的电和磁的极化状态(而不是通常假设的两个),可获得额外信道容量.根据短波移动通信散射环境不断改变的特点,通过测试螺旋天线(终端加鞭天线)接收综合极化信道的话音质量与距离的关系,比较了同频率同距离(200 km以内)条件下,螺旋天线、斜拉天线和双极天线的话音质量的差异,这3种不同极化天线的话音等级均在1以上,表明在载体上接收的电磁极化方向不再是单一的水平极化波或垂直极化波.提出了一种能够接收有6个可区别的极化状态的多极化天线系统模型,在散射条件下,能充分利用不同极化的独立空间信道收发同一信息,提高了短波移动通信的可靠性.

The independent channel capacity obtained in a scattering environment is three times more than that gained in the free environment. The extra channel capacity is gained because there are six distinguishable electric magnetic states of polarization at a given point, rather than two as is usually assumed. According to the characteristics that the scattering environment in which HF radio transmission spreads is always changing, comparisons are made by testing the relations between the voice quality of the composite polar channel voice received by a printed helix antenna （loaded whip antenna in the terminal） and distance. After comparing horizontal polarization, vertical polarization with circular polarization in tone quality for transmitting at the same frequency and distance （within 200kin）, a relationship is given between tone quality and transmitting distance. The voice levels of all three different polarization antennas are above 1, which shows that the electric and magnetic polarizations received on the carriers are not single horizontal polarization or vertical polarization. The experiment shows that the reliability of HF mobile communication can be raised by transmitting or receiving the same message through different polarizations. Based upon this theory, a novel model of multiple polarization antenna system is presented.