Design of a multi-band frequency reconfigurable planar monopole antenna using truncated ground plane for Wi-Fi, WLAN and WiMAX applications

Abstract

Reconfigurable or switchable antennas are potential candidates for modern wireless and portable devices to operate at more than one frequency bands, polarizations and scanning radiation patterns in accordance with user requirements. This paper describes the design of multi-band frequency reconfigurable 7-shaped planar monopole antenna, employing 1.6 mm thicker FR4 as a substrate material and a truncated metal ground plane. The antenna operates in single as well as dual-band frequency modes depending on the state of the switch used. The proposed antenna operate in the dual frequency mode (Wi-Fi at 2.45 GHz and WLAN at 5.4 GHz) and single frequency mode (WiMAX at 3.5 GHz) when the optical switch is in ON and OFF states respectively. The bandwidths achieved are 20, 39 and 9.3% centered at 2.4, 3.5 and 5.4 GHz, frequencies respectively. The antenna is impedance matched (i.e. input impedance=51∼54 Ω) resulting in VSWR< 1.3 for the three frequency bands. Satisfactory gains of 1.92, 2.41 and 3.02 dBi and efficiencies of 86.5, 85 and 74.6% are attained at 2.45, 3.5 and 5.4 GHz frequencies respectively. Printed monopole reconfigured antennas are small, low profile and light-weight which can be used in portable electronics (mobile phones, iPads, PDAs and laptops) and wearable applications (safety and rescue operations). The antenna scattering and far-field parameters are evaluated using a numerical Finite Integration Technique (FIT) and Finite Element Method (FEM) employed in CST MWS and HFSS, respectively.