An antenna is a transducer that converts between electrical signals and electromagnetic waves.
- In transmit mode it radiates RF energy into free space
- In receive mode it captures incoming RF energy and delivers it as an electrical signal to the Receiver.
- An antenna is a passive component, it only converts signals. This is different from a Radar which is a complete active system that uses an antenna (or multiple antennas) as one part alongside a Transmitter, Receiver, and signal processor to detect and locate objects.