Mutual coupling between dual-band microstrip antenna array elements

The dual band antenna element described by the authors offers a good economy in element packing and an intermediate range of frequency ratios (typically 4:1). Preliminary results on a circularly polarised (CP) probe-fed version of the element indicated good pattern characteristics at both frequencies, though some reduction in bandwidth for the low frequency patch and an increase in mutual coupling for the high frequency elements have been noted. The authors concentrate on the design aspects of mutual coupling and coupling mechanisms for window elements