An Omni antenna, like the simple rod antennas, transmits and receives about same in all directions except off the ends on the antenna where there are dead zones. So, don’t point the receiver antenna at the transmitter antenna or vice versa.
Also, rod antennas polarize the transmit and receive signals such that vertical antennas are vertically polarized and horizontal antennas are horizontally polarized. Therefore, keep the transmit and receive antennas parallel for best results.
An antenna with gain flattens or focuses the transmit and/or receive signal patterns; i.e., they squeeze the available radio energy into a tighter pattern. So, higher gain antennas tend to be directional. They work better in one direction but not as well or at all in other directions. Low-gain antennas are more forgiving in this respect. High-gain antennas are not necessarily better.
A patch antenna is directional. The transmitter needs to be in a direction perpendicular to the plane of the receive antenna for best results.
Clover leaf and patch antennas are circularly polarized. They can be made to have clockwise or counterclockwise polarization.
in any case, match the type, polarization, and orientation of the transmit and receive antennas for best results. If you tend to fly all around you, low-gain vertically polarized rod transmit and receive antennas may be best (never point the antennas at the quad). If you can keep the UAV out in front of you, antennas with some gain/direction may be best.
The above is based on ideal conditions. In the real world, antennas also pick up reflected signals and radio signals are polarized by reflecting surfaces, so even mismatched antennas can work to some degree. Still, you should get better results if you match the antennas, etc.
Finally, 2.4 and 5.8 MHz radio frequencies are short wave lengths that travel in straight lines, i.e., they are line of sight except for reflected signals. And just like light, these high radio frequencies are attenuated by just about everything (buildings, hills, trees, people, etc.). If you can’t see through it, neither can the radio equipment you are using to control your aircraft. Any signals that get through or around attenuating stuff are reflected, depolarized, weaker signals.
All of the stuff mentioned above are what cause signal loss/“interference.” If you fly analog equipment, get used to it, it’s not going away. Digital equipment can reduce but not eliminate the problem.
