LAUSR

A dual-band antenna operating in dual bands is presented. The antenna is composed of two substrate layers covered with three printed patch layers. The top layer is an electrically small ring; the middle consists of four spiral resonators (SRs); and the bottom is a split-ring resonator (SRR). Inductive couplings between layers change the radiation Q factor of the original ring antenna and promote resonating modes in UHF and S bands. Besides, the input matching property is also improved. The measured return loss agrees well with the calculated results, and the radiation patterns are also presented. From experiments it is found that the proposed antenna is electrically small at operation dual-bands.