Design and Measurement of a Wideband Aperture-Coupled and Polarization-Agile Stacked-Patch Antenna-Array for Monopulse Radar Applications
Conference: EuCAP 2009 - 3rd European Conference on Antennas and Propagation
03/23/2009 - 03/27/2009 at Berlin, Germany
Proceedings: EuCAP 2009
Pages: 4Language: englishTyp: PDFPersonal VDE Members are entitled to a 10% discount on this title
Methfessel, Sebastian; Schmidt, Lorenz-Peter (Institute for Microwave Technology, University of Erlangen-Nuremberg, Cauerstr. 9, 91058 Erlangen, Germany)
A wideband, circularly-polarized antenna array covering the frequency range 1.7 GHz to 2.5 GHz for telemetric monitoring and monopulse application is presented. Using a subarray design, monopulse functionality can be achieved with an external comparator network. The high bandwidth of 38 % is realized by using the principle of the aperture-coupled stackedpatch microstrip antenna. By integrating a quadrature coupler, the polarization sense can be selected. Sequential rotation technique is used for enhancing polarization purity. The theoretical analysis is based on the finite-difference time-domain (FDTD) method. A stacked-patch antenna element, a 2x2 antenna quadrant and a 4x4 antenna array have been designed, fabricated and measured. The measured return loss of one quadrant is better than 11 dB in the desired bandwidth for both circular polarization senses. Maximum antenna gain ranges between 7 dB and 18 dB for the sum pattern while the null depth of the difference pattern is always better than 30 dB. Theoretical and measured results of S parameters and radiation patterns are presented and discussed.