DESIGN AND MEASURED PERFORMANCE OF DUAL POLARISED APERTURE-COUPLED MICRO STRIP PATCH ANTENNAS

The paper discusses the design of aperture-coupled microstrip patch antennas for dual linear polarisation with special emphasis on achieving a wide bandwidth and a high polar- isation isolation. The coupling behaviour of crossed slot and offset slot designs is discussed and compared to each other. Several design examples for aperture-coupled antenna ele- ments illustrate how the polarisation isolation decreases as the bandwidth of the antenna elements is increasing. A design example for an 8xl element subarray for a frequency in X- band (9.6 G Hz) shows a standing wave ratio of VSWR< 1..5 and a polarisation isolation of better than 2.5 dB within a bandwidth of 470 MHz