This article presents a novel offset-fed technique to achieve impedance matching for a planar inverted-L antenna (ILA). The offset-fed ILA exhibits dual band characteristic (fre. ratio ∼ 3:1) similar as the straight monopole antenna. For dual-band operation with frequency ratio other than (3:1) a parasitic rectangular strip is introduced for the offset-fed ILA antenna. Dual-band ILA antennas operate both at 2.4 and 5 GHz (5.2 or 5.8 GHz) bands are successfully designed. The simulated and measured results are very consistent. Moreover, the designated two bands can be adjusted independently by simply varying the corresponding lengths.
Microwave and Optical Technology Letters 56(5), pp.1244-1248