DESIGN OF A TUNABLE DUAL-BAND LOOP ANTENNA

Abstract

A dual-band frequency tunable loop antenna that utilized a circuit model was introduced. An open loop antenna was selected as a prototype, which could be simply represented by an LC resonant circuit. To overcome the input mismatch in high-frequency region, an additional a circuit was introduced. Using a chip inductor in the pi circuit, the high frequency can be easily tuned without changing the low frequency. The proposed dual-hand antenna performs better than the single-band antenna. Both the simulated and measured results agreed well. The proposed antenna was compact (0.09) lambda(0) x 0.09 lambda(0) x 0.01 lambda(0)) and operated at two different frequencies (1.80 and 2.45 GHz). The operating bandwidth (S-11 < -6 dB) was 1.7-2.7 GHz, satisfying GSM 170011800, WCDMA, and, WLAN. (C) 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:2207-2212, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26246