Development of a microstrip antenna for a miniaturized transponder

A circular polarized aperture fed microstrip patch antenna operating at 5.3 GHz have been designed, simulated, manufactured and verified. The antenna is part of a miniaturized transponder for Synthetic Aperture RADAR, SAR, applications. The idea of the transponder is to use it for tagging purposes wherever objects, for example personnel or vehicles, need to be identified. For this reason the transponder has to be small and lightweight. Former transponders have used separate transmit and receiving antennas, here the same antenna will be used for both transmit and receive. The transponder will be operated with the European Space Agency, ESA, satellites ERS-2 and ENVISAT, as well as the DLR airborne SAR-system E-SAR, all operating in C-band. Satellites not yet launched are the high resolution satellites TerraSAR-X, to be launched in October 2006, and SAR- Lupe, 5 satellites of which the first is to be launched during 2006. Both TerraSAR-X and SAR-Lupe operates in X-band. The selected antenna type is the microstrip patch antenna. Several different designs are considered and finally the chosen design is an aperture fed microstrip patch antenna with rectangular patch and dual orthogonal feeds with a Wilkinson power divider. Measurements for verification of the antenna are performed with a network analyser and at an antenna test range.Validerat; 20101217 (root