Why log or yagi DVBT antennas are installed in horizontal polarization, while transmitters are vertical monopoles? We are talking about 470MHz-862MHz antennas. The antenna is as below: https://www.antene-zupancic.si/dvb-t-antena-iskra-p-20-dtt-z-ojacevalnikom/
As far as I know, log or Yagi DVB-T antennas go horizontal to catch signals better over longer distances and avoid troubles with vertical signals. On the other hand, transmitters rock vertical monopoles because they're easier to set up and have less signal loss close to the ground.
There are a few reasons why log or yagi DVBT antennas are installed in horizontal polarization, while transmitters are vertical monopoles.
- Horizontal polarization is more resistant to multipath fading. Multipath fading is a phenomenon that occurs when the signal from the transmitter arrives at the receiver via multiple paths, such as reflected off of buildings or other objects. This can cause the signal to be weakened or distorted. Horizontal polarization is less susceptible to multipath fading than vertical polarization.
- Horizontal polarization is more efficient at transmitting through foliage. Foliage can absorb and scatter radio waves, which can reduce the signal strength. Horizontal polarization is less affected by foliage than vertical polarization.
- Horizontal polarization is more compatible with rooftop antennas. Most rooftop antennas are designed for horizontal polarization. This is because horizontal polarization is more efficient at transmitting through the atmosphere.
On the other hand, vertical monopoles are used as transmitters because they are:
- Simple and inexpensive to construct.
- Easy to mount on towers or other tall structures.
- Reliable and durable.
In some cases, transmitters may also be using horizontal polarization. This is often done in areas where there is a lot of multipath fading, such as in urban areas.
Ultimately, the choice of polarization for a DVBT antenna depends on the specific application. In most cases, horizontal polarization is the preferred choice for receivers, while vertical polarization is the preferred choice for transmitters.
OK, thank you, but in ideal case receiver should receive nothing when transmitter is verticlly polarized, while receiver horizontal polarized. In real life this "nothing" can result in -20dB loss. I understand all your points, but loosing 20dB due to polarisation is better, than multipath and foliage attenuation. As well how this polarization converts from vertical to horizontal (I believe this can happen due to reflection, multipath and propagation through various media that is very unstable). What would be your thoughts?
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