Wideband Omnidirectional Printed Dipole Antenna with Coupling Feed for Wireless Communication Applications
The wideband and omnidirectional performance of a printed dipole antenna with a novel coupling feed structure is presented. Besides using printed dipole for omnidirectional radiation patterns, the coupling feed structure, which includes the transmission line coupling to a slot line to effectively improve the impedance matching, can be used for bandwidth enhancement. A wideband impedance characteristic of about 45.6% for VSWR ≤2 ranging from 1.54 to 2.45 GHz is obtained. The omnidirectional radiation patterns in the whole operation bands are achieved which the un-roundness in H-plane is less than 1.6dB. It is sufficient for accommodating recent wireless communication services such as DCS1800, PCS1900, UMTS, IMT2000, Wibro, etc. Furthermore, the proposed antenna should be a good candidate as a unit of the omnidirectional array. A prototype has been fabricated and tested, and the experimental results validate the design procedure.