In-flight experiment for combined planar antennas and solar cells (SOLANT)

An in-flight experiment to validate advanced solar antenna structures (SOLANT) in space is presented. Two different antennas have been designed and manufactured, one for Global Positioning System (GPS) reception and one for S-band beacon transmission. Both units use slot aperture radiators embedded in identical mechanical structures. The GPS antenna has been designed to generate an omni-directional radiation pattern with right-handed circular polarisation thus fulfilling NavStar specifications. The S-band beacon antenna is based on a four-element circularly polarised array providing 6 dBic of gain. These antennas are integrated within two solar panels, which form the upper layer of the antenna structure. The two panels are identical, make use of gallium arsenide (GaAs) solar cells arranged in two strings and provide a peak power of 10 W each. The SOLANTs were launched, fixed to a Cosmos payload adapter and remained operative for 2 years, well beyond their expected lifetime. This study summarises the design and performance tests performed prior the launch and during the orbital operation.