ERA designs and supplies not only complete antenna systems, but also feed chains and feed components. ERA expertise includes multi-band feeds and complex tracking subsystems based on monopulse or electronic lobe switching configurations.

A critical component in any reflector antenna is a feed chain, its complexity being dependent on the number of functions that it has to provide. In its basic form, a feed chain consists of a corrugated horn, which illuminates a reflector, a polariser that converts linear polarisations into circular and vice versa and an orthogonal mode transducer (OMT). An OMT is a waveguide component, generally a three-port device, that allows simultaneous reception/transmission of vertically and horizontally polarized signals. The input port is typically a circular waveguide. The two output ports are rectangular waveguides.

Of major importance is the radiation performance of the corrugated horn, which, in general, must be able to propagate communication channels without exhibiting any unwanted reflections or mode conversion; a matching section is also required to realise a good overall VSWR performance. Sophisticated in-house computer software employing accurate mode matching techniques is available at ERA for feed horn design for applications in any frequency band. Similar software is used for the design of other feed chain components including polarisers, orthogonal mode transducers and filters.

Tracking feed systems
For applications where it is necessary to ensure accurate pointing of the antenna towards the satellite, ERA is able to supply one of a number of antenna tracking solutions. For high tracking sensitivity, which might be required for Tracking, Telemetry and Control (TT&C) applications, ERA has provided monopulse systems employing higher order waveguide modes. Where it is a requirement to maintain a high data rate communications link in a highly dynamic environment, ERA has a novel electronic beamsquint tracking system which offers high tracking sensitivity without the need for a high cost tracking receiver.

C and Ku Band feed chain for a Cassegrain antenna		20/30 GHz Feed chain for single offset reflector
20/30 GHz Feed chain for Cassegrain antenna		Deep Space Tx/Rx Ka Feed chain
20/44 GHz Feed chain for offset reflector		4/6 GHz Feed chain for Cassegrain antenna