Receiver Antenna
This is the passive component that connects to the receiver and converts the radio signal into an electrical signal. It is included in the box contents of AXI sets. Because it is the single part that affects range the most, its position and integrity can be more decisive than the choice of receiver itself; a damaged or wrongly placed antenna reduces the working distance many times over.
The antenna is the only passive but most critical part of the system. Whatever the sensitivity of the circuit board may be, a signal that does not reach the antenna cannot be received. For that reason, on range complaints the first place to look is not the transmitter or the receiver but the antenna.
The factors that determine an antenna's performance:
- Position: it should be a few centimetres away from metal surfaces and, if possible, outside the panel.
- Orientation: a vertical position is generally preferred; the transmitter antenna is also mostly vertical, and polarisation match directly affects the signal level.
- Integrity: a crushed, broken antenna or one with a loose connector creates a measurable loss.
- Cable: the antenna cable is not shortened or extended; the length and impedance match would be spoiled.
For a working distance that shortens over time, the check sequence is this: first the transmitter battery, then the antenna and its connector, then any interference sources newly added to the environment (inverter, welding machine), and last the receiver placement. When fixing the antenna to the panel, take care that it does not touch the body metal and does not rub against it with vibration.
The context in which this term is used: 433 MHz or 2.4 GHz?