The Model ATC25M1G Cavitenna was developed specifically for use in a shielded room of the type commonly used for RF susceptibility testing. The Cavitenna is a small, broadband radiator designed to couple energy into the shielded room as though it were a resonant cavity. Because a shielded room is a space bounded by electrically conducting surfaces, it has all the properties of a resonant cavity. The Cavitenna achieves its unusually small size by using the wall of the shielded room as its grounded plane. This design frees the Cavitenna from size constraints inherent in antennas designed for free space application. When excited as a cavity, a shielded room has many resonant modes determined by its geometry. Field polarization and phase performance cannot be controlled when an RF radiator is placed within a shielded room. AR RF/Microwave Instrumentation has designed the Cavitenna so that it can easily be moved from wallto- wall to obtain different phase and polarization. For highly automated systems, three Cavitennas are recommended for mounting on the walls of the shielded room. This arrangement used with automatic switching, enables successive testing with different phase and polarization conditions generated by each antenna. The Cavitennas unique combination of small size, extremely broad frequency range, and tolerance for high RF voltages, when used with the resonant cavity characteristics of a shielded room, significantly reduces the RF power and time required for RF susceptibility testing.
