For line – of – sight communication the transmit and receive antennas should face each other. If the transmit antenna is vertically polarized, then for best reception the receiver antenna should be:
which one from the below?
Horizontally polarized
At 450 with respect to horizontal polarization
Vertically polarized
At 450 with respect to vertical polarization
Dear KUMAR;
The correct way of reception is that the two antennas (transmit and recevier) must have the same polarization otherwise it will have a fading. So, for your case the receiving antenna must be vertically polarized.
Best is to have vertical polarized antenna. But you can also go for circular polarization if there are sources of reflection in between, as if there is polarization mismatch due to any reason the losses will be more than that in case of vertical to circular reception(only 3dB in case of vertical to circular but may be as high as 25dB in case of mismatched vertical to vertical reception).
In the LoS case, vertically. No doubt. You may consider the receiving antenna as a "slot" through which your "vertical wave" must go. If it is not vertical (maybe that 45º you mentioned) some part of the wave may go through the slot (nothing at all if it is horizontal), but the best choice is the vertical slot so that the complete wave may pass through it. I hope this metaphore helps.
It is true that other cases may differ: reflections, por example, may change the polarization of your wave; but in any case the best choice is a fit between the antenna and the received wave.
- Badges
- Science topic