A novel dual-frequency monopole antenna for WCDMA and 2.5 GHz extension band

A new dual-frequency design of microstrip monopole antenna is proposed and experimentally studied. The two operating modes of the proposed antenna are associated with various lengths of two monopoles, in which the longer monopole works for the first resonant mode and the shorter monopole works for the second mode. Meander microstrip line is designed to reduce the size by 38%. Moreover, by etching rectangular slot in the longer monopole, a broadband dual-frequency operation is demonstrated. Experimental results show that the impedance bandwidth, determined from 10-dB return loss, of the two operating frequencies is 14.6% and 11% respectively. The proposed dual-band antenna can be used in the WCDMA band (1920-1980 MHz, 2110-2170 MHz) and the 2.5 GHz IMT-2000 extension band.