Stub Loaded Rectangular Ring Shaped Tri-Band Monopole Antenna for Wireless Applications

This paper presents, design and equivalent circuit analysis of tri-band parasitically stub loaded rectangular ring printed monopole antenna for wireless communication applications. The printed monopole antenna is designed, fabricated and tested. The measured impedance bandwidth (S11< -10 dB) is 750 MHz (2.22 – 2.97 GHz), 220 MHz (3.65 – 3.87 GHz) and 1.28 GHz (5.23 – 6.51 GHz) covering Wi-Fi, WiMAX and WLAN/Wi-MAX applications respectively. The electrical dimension of monopole is 0.245λ0 × 0.212λ0. The proposed antenna is simple and a low profile structure fabricated using low cost glass epoxy substrate (FR4). The overall size of antenna is 60 × 40 mm2. Using slot cut and parasitically coupled stub loading methods, the tri-band monopole antenna has been realized and measured results are found to be in good agreement with simulated results. The equivalent circuit analysis and mutual coupling between the slots are calculated and presented.