Compact broadband circularly polarized square microstrip antenna

Abstract

A new design for achieving compact broadband circular polarization (CP) radiation of a square microstrip antenna is presented. The compactness of the microstrip antenna is easily obtained by inserting four slits of equal lengths at the patch edges, and broadband CP radiation is achieved simply by loading a chip resistor at a proper position in the patch. The present proposed CP design has been implemented with an increase of about 50% in CP bandwidth as compared to the compact CP design using inserted slits of unequal lengths. Details of the antenna design and experimental results are presented and discussed. ©1999 John Wiley & Sons, Inc. Microwave Opt Technol Lett 21: 423–425, 1999.