Combline Loadings of Printed Triangular Monopole Antennas for the Realization of Multi-Band and Wideband Characteristics

In this paper, we use the concept of stub loadings of planar microstrip antennas to convert a single band antenna into a dual-band antenna used for WLAN. We load a planar triangular monopole (PTM) antenna by combline stubs attached to the edges of patch in order to obtain a second resonance frequency. The simple PTM antenna is first designed to produce the lower resonance frequency and the geometry of combline stubs is then optimally designed to generate the higher resonance frequency to realize a dual-band or a wideband antenna. Three prototype models of PTM antennas are designed, fabricated and measured. Their performances verify the concept of inductive loadings of planar antennas by combline stubs for the realization of dual-band and wideband performance for WLAN.