A Novel Compact Dual-band Capacitive-Loaded Printed Monopole Antenna

In this paper, the proposed design of a novel compact antenna, consisting of a notched planar monopole and a capacitive-loaded patch is printed on the opposite side of an electronically thin dielectric substrate and fed with a 50 Omega microstrip line. The antenna can provide two separate impedance bandwidth of 500MHz (about 18.7% centered at 2.675GHz) and 1.6GHz (about 31.2% centered at 5.13 GHz) with return loss S11 below -10dB. It easily covers the required bandwidths for wireless local area network (WLAN) in this design. By adjusting the lengths of the planar monopole and capacitive-loaded patch, resonant frequencies can be tuned to suitable bands for WLAN operation. Widths can control the impedance matching for the dual band. And in the design a triangular is connected between 50 Omega microstrip line and planar monopole to achieve a good impedance match. Details of the design considerations of the proposed antenna and experimental results are presented and discussed later.