Compact Multiband Microstrip Printed Slot Antenna Design for Wireless Communication Applications
In this paper, a compact multiband printed antenna is proposed to cover four resonant bands in the range of 1 6 GHz. The antenna structure is inspired from that of the classical multi cavity magnetron resonator. The antenna comprises a slot annular ring structure in the ground plane of an Isola FR4 substrate having r 3.5 and thickness h=1.5 mm. The outer circle of the annular ring is loaded with radial arranged small circular slots. On the opposite side of the substrate, the antenna is fed with a 50 Ohm microstrip line. To investigate the effect of different antenna elements on the antenna performance, a parametric study is conducted. The antenna is simulated, fabricated, and measured. The simulated 10 dB return loss bandwidths for the four resonant bands are 35% (1.53 2.11GHz) 14% (2.9 3.34GHz) 12% (4.2 4.75GHz) and 9% (4.94 5.39GHz) respectively. Thus, the antenna is a proper candidate for many in use bands of wireless systems (1.65, 3.14, 4.44, 5.24 GHz) including LTE FDD, GNSS, GSM 450, W CDMA/HSPA/k, 802.11a, and IEEE 802.11ac WLAN. The results indicate that the designed antenna has quad band resonant responses with substantial frequency ratios of f4/f3, f3/f2 and f2/f1. Besides, the antenna offers reasonable radiation characteristics with a gain of 2.5, 4.0, 6.2, and 4.2 dBi, throughout the four resonant bands.