Compact gap-coupled shorted 90 degrees sectoral microstrip antennas for broadband and dual-band operations

Compact gap-coupled shorted 90 degrees sectoral microstrip antennas (MSAs) have been proposed whose bandwidth is 2.5 times the bandwidth of the corres ponding circular MSA (CMSA) with half the area. By partially shorting the 9 0 degrees sectoral MSA, the broadband response is obtained at a lower frequ ency, leading to a further area reduction. Tunable dual-band operation has been obtained by increasing the coupling between the two parches rising a s horting strip for both a single-short and a fully shorted 90 degrees sector al MSA. (C) 2000 John Wiley & Sons, Inc.