EXPERIMENTAL INVESTIGATIONS ON THE IMPEDANCE AND RADIATION PROPERTIESOF A 3-ELEMENT CONCENTRIC MICROSTRIP SQUARE-RING ANTENNA

Experimental investigation on an electromagnetically coupled concentri c microstrip square-ring antenna (CMSRA) kos been presented. Our previ ous work on concentric microstrip annular-ring resonators revealed tha t the impedance and radiation bandwidth can be improved considerably. A three-element CMSRA has been designed and its measured impedance and radiation patterns have been compared with those of a single square-r ing antenna having a dimension equal to the largest element of the CMS RA. The effect of change of feed location has also been studied. Resul ts show that the total percent bandwidth (BW) for the concentric micro strip square ring antenna is larger with respect to the single-ring an tenna, and this effect is very much prominent at a particular feed loc ation. (C) 1996 John Wiley & Sons, Inc.