MULTI-BAND CHIP ANTENNA FOR WiMAX APPLICATIONS

摘要

A novel chip antenna for dual-/tri-band operation is presented in this article. The design consists of a pair of forked metal strips with different lengths. The longer strip is folded onto an FR4 base to simultaneously introduce the quarter- and half-wavelength modes as the first two operating bands. By varying the included angle between the sections of strip on the opposite base layers, the frequency ratio of the first two operating modes is adjusted over a large range of 1.34-2.29. In addition, the shorter excited strip introduces the quarter-wavelength mode as the third operating band. The tri-band operation with a small dimension of 13×5×0.8 (mm)~3 for 2.5/3.5/5.5 GHz WiMAX applications is implemented. Experimental results show that the proposed antenna has good omnidirectional radiation patterns and steady antenna gains over all operating bands.