why antenna should have horizontal polarization
In one paper stated, that their receiving antennas should be omnidirectional and have horizontal polarization. Why they need horizontally polarized antennas for that?
Thanx
given that you havent given us any context for who "they" are or what "they" are trying to do
for a horizontally polarised antenna to be near omni directional it would have to be a loop
pretty much any other form of horizontal antenna WONT be omni-directional
Dave
In 1930's RCA discovered on their first TV broadcast transmissions in VHF bands that horizontal polarization gave better reception at greater distances than vertical polarization.
In line-of-sight (LOS) is almost no difference between H and V polarization, but when the waves starts to follow the horizon curvature (beyond line-of-sight BLOS), H polarized waves propagates longer distances due to ground enhanced tropospheric scatter.
When Brits were driving on the wrong side of the road, their TV antennas had vertical polarization and their signals reflected like mad off tall buildings.
As an omnidirectional characteristic is usually unwanted for a TV antenna, it's unlikely that the paper refers to TV antennas.
In fact, omnidirectional directivity can be mostly found with vertically polarized antennas, e.g. for GSM, FM-radio, WiFi.
Thank you all for replies.
The paper is denoted to antenna array for radar application. And yes they used loop antennas, but I can't understand what's advantage of using antenna with horizontal polarization in this case (especially when, as what previously mentioned, most of omni antennas have vertical polarization).
Maybe it is related to reflection.
Radar emits a H wave, then receives a H wave.