SAR experiments using a conformal antenna array radar demonstrator

Conformal antenna arrays have been studied for several years but only few examples of applications in modern radar or communication systems may be found up to date due to technological difficulties. The objective of the "Electronic Radar with Conformal Array Antenna" (ERAKO) demonstrator system currently being developed at the Fraunhofer Institute for High Frequency Physics and Radar Techniques FHR is to demonstrate the feasibility of an active electronically scanned antenna for conformal integration into small and medium sized airborne platforms. The system is based on a wing or fin type elliptical profile with a strong degree of curvature and in its current state consists of more than 24 patch antenna sub-arrays for operation in the X-Band with a relative bandwidth of more than 15%. For practical trials the antenna has been adapted for operation with the Phased Array Multifunctional Imaging Radar (PAMIR) system developed at the institute. For integration into the system, the antenna needed to undergo a special calibration procedure for beam forming and imaging post-processing. The present paper describes the design and development of the antenna front-end of the demonstrator system, its connection to the PAMIR system and results of recently conducted synthetic aperture radar (SAR) experiments.