A novel, very low profile, dual band inverted ‘e’ monopole antenna for wireless applications in the laptop computer

Abstract

A novel, very low profile and ultra-thin inverted ‘E’ shaped monopole antenna for WLAN/WiMAX applications in the laptop computer is presented. The thickness of the antenna is only 0.2mm and is designed using only a pure copper strip of size 20 × 6mm2. The innovation of the design is miniaturized size and wider impedance bandwidth in dual band operation using two monopole radiating strips namely RS (inverted J) and PQ (inverted Z) along with open ended vertical tuning stub of size 4.5 × 1mm2. The measured impedance bandwidth spanned as 11.24% (2.35–2.63)GHz in a lower band (Fl) and 18.78% (4.92–5.94) GHz in the upper band (Fu) for VSWR < 2 and covers 2.4/5.2/5.8GHz WLAN and 5.5 GHz WiMAX bands. The presented antenna has proved excellent radiation performance, including nearly omnidirectional patterns, a stable gain of around 4 dBi and an excellent efficiency of around 90% in Fl and Fu bands. This confirms the applicability for WLAN/WiMAX applications in the prominent ultra-thin laptop computers.