Design of a printed quarter-elliptical wide-band antenna for portable devices

Abstract

The paper presents an approach to design a compact wide-band antenna spanning a frequency of 1.5-3.5GHz. This encompasses the upper UMTS, WLAN and GPS bands used by many portable devices. A planar elliptical monopole is first adapted for corner-placement and feed within a device. The primary element is then modified to resemble a quarter ellipse, supported by a large ground plane. Using computer simulations, the resulting structure is confirmed to operate within the 10dB return loss reference from 1.9 to 3.0GHz with reasonable performance at 1.5GHz. The design is further reduced in size by careful manipulation of the ground plane dimensions, supporting an additional resonance at the lower frequencies. The final design is confirmed by measurement to provide good return loss from 1.5 to 3.5GHz.