Reconfigurable Antenna with Omni-/Bi-directional Patterns for Wireless Applications

A reconfigurable antenna for omnidirectional or bidirectional radiation with horizontal polarization is proposed in this paper. The reconfigurable antenna is made up of a two-layer Alford ring for omnidirectional radiation and split-ring patches over a metal disk for bidirectional radiation. Eight interdigital capacitors are introduced on the Alford ring for bandwidth enhancement for omnidirectional radiation. The antenna is reconfigured by switching working states of five PIN diodes that integrated on the antenna. It is shown that the proposed antenna achieves horizontally polarized omnidirectional or bidirectional radiation patterns with good impedance matching over the frequency band of 5.15-5.85 GHz.