Beam waveguide antenna

A beam waveguide antenna is a particular type of antenna dish, at which waveguides are used to transmit the radio beam between the large steerable dish and the equipment for reception or transmission, like e.g. RF power amplifiers.

In high performance systems, complex transmitter and receiver electronics must be located at the feed antenna.

Furthermore, the feeds themselves have to be designed to handle outdoor conditions such as rain and large temperature swings, and to work while tipped at any angle.

The radio waves collected by the dish are focused into a beam and reflected by metal surfaces in a path through the supporting structure to the stationary feed antenna at the base.

[4] At first, it was believed the complicated signal path with its multiple reflecting surfaces would result in unacceptable signal loss[5] but further analysis showed the waveguide system could be built with very low losses.

Diagram of a beam waveguide antenna from NASA, showing the signal path (red)
34-meter beam waveguide antenna at NASA's Deep Space Communications Complex site outside Madrid, Spain, part of the NASA Deep Space Network .
Beam Waveguide Antenna Schematic
An example of one of the practical difficulties that led to the introduction of beam waveguide antennas. Here a cherry picker type truck is needed to allow workers to re-load liquid helium into a pre-amplifier mounted at the prime focus of a radio telescope. [ 1 ]