Dual-band elliptical wide-slot antenna with high BDR for portable wireless applications.

This paper presents a highly compact dual-band elliptical wide-slot (EWS) antenna with high bandwidth dimension ratio (BDR) having one inverted L-slot for WLAN and WiMAX applications. Initially, the broadband characteristic of 4.4–9.3 GHz is obtained by using an EWS in the ground plane. To include 3.5 GHz WiMAX wireless standard, a parasitic elliptical patch is embedded in the centre of the elliptical wide-slot. With an increase in semi-major axis length of the parasitic patch, the overlapping capacitance between the microstrip-line and the parasitic patch increases, thereby showing a broadband characteristic ranging from 3.59 to 7.08 GHz and BDR of 1423. An inverted L-shaped slot is etched in the ground plane to generate a frequency band around 2.4 GHz, integrating the 2.4 GHz WLAN and 2.5 GHz WiMAX wireless standards. The measured 10 dB return loss bandwidth due to mirrored L-shaped slot is 440 MHz (2.34–2.78 GHz) with BDR of 923. As a result, the EWS with parasitic patch and mirrored L-shaped slot together gives an overall size of 0.132 λ L × 0.14 λ L where λ L is the lowest free-space wavelength corresponding to the operating frequency of 2.34 GHz. The measured peak gain of lower and upper-frequency bands is 6.95 and 6.82 dB. [ABSTRACT FROM AUTHOR]