Egg beater antenna
Image of the Egg beater antenna.

The "Eggbeater" antenna is an example of an electrically large antenna consisting of a pair of orthogonal loops each with circumference of one wavelength. This simple, robust antenna is ideal for operating in UHF and VHF bands, is capable of withstanding extreme weather conditions (including high wind-loading) and is easy to assemble and transport.

The antenna configuration is equivalent to two pairs of horizontal dipoles, orthogonally positioned, with a 90 degree phase difference. This gives the eggbeater the radiation characteristics of being left- or right-hand circularly polarised in the zenith direction and horizontally polarised on the horizon. This makes it ideal for omnidirectional satellite communications. For example the SANAE base in Antarctica uses an Egg-beater antenna on their satellite base station where it has to survive extremely low temperatures (below -50 o C) and has to withstand strong (> 160km/h) winds.

Right-hand circular and left-hand circular radiation patterns at the operating frequency for a right-hand circular design are shown below. The polarisation is linear on the horizon and becomes more circular at greater elevation angles.

RHC and LHC radiation patterns at the design frequency.