• Antennas are devices that launch energy into space around
them in the form of electromagnetic waves.
• Or, in the reverse process, extract energy from an existing
These properties are used for:
- Telecommunications, broadcasting
- Active Remote Sensing: electromagnetic waves are
transmitted to "illuminate" an object, and returning echoes
are detected and analysed.
- Passive Remote Sensing
- Energy Transmission: medical applications, satellites.
- Electronic Warfare: enemy communications are disrupted.
• An antenna is also defined as a transducer, an element
between a transmission line and the free space where the
electromagnetic wave propagates.