Ultra-wideband reconfigurable radiation pattern antenna for diversity applications

A radiation pattern reconfigurable planar antenna operating at an ultra-wideband frequency range of 2.78-10.85 GHz is proposed. The proposed antenna is a combined structure of a monopole and a tapered slot, and it has two types of radiation patterns that can be chosen to be a monopole pattern or tapered slot pattern by controlling the states of four diodes. In addition, the shape of both radiation patterns is maintained across the whole operating frequency range. Details of the operation principle and the design considerations of the proposed antenna are presented.