Empirical Model for the Design of Printed Butterfly Antennas

An empirical model for the synthesis of microstrip butterfly antenna without ground plane is proposed in this work. A fast design method, properly taking into account the effect of feed connector, is discussed to obtain a compact radiating element (75 % reduction with respect to standard patch antenna), with a large bandwidth (about 18 %) and an excellent rejection of cross-polar field components. Experimental validations on an UHF butterfly antenna prototype are discussed to show the effectiveness of the approach.