A Planar Reconfigurable Radiation Pattern Dipole Antenna with Reflectors and Directors for Wireless Communication Applications

A planar printed dipole antenna with reflectors and directors, able to steer its radiation pattern in different directions, is proposed for telecommunication applications. Starting from a dual-beam printed dipole antenna achieved by combining two elementary dipoles back to back, and by loading four PIN diodes, three modes of reconfigurable radiation patterns are achieved at the frequency 2.56？GHz thanks to switches states. A prototype of the structure was realized and characterized; an efficiency of 75% is obtained. Simulation and measured results of the results are presented and discussed. 1. Introduction In the latest years, reconfigurable radiation pattern antennas are becoming more and more desired because of the increasing demands on the quality and capacity of the telecommunication systems. The capability to steer the beam’s directions electronically extends the functionalities of the antennas and adds more flexibility. In addition, the radiation pattern agility characteristic contributes on avoiding noisy environments, improving security, and saving energy by better directing signal toward intended users which enhance the overall performances of the modern wireless communication systems. Several reconfigurable radiation pattern antennas have been reported such as a three-layer switchable radiation pattern antenna based on the conventional Yagi antenna [1], an hexagonal cylinder antenna with moderate gain of 5？dBi [2], and a central circular patch with two paddle-shaped parasitic patches [3]. Among many types of reconfigurable antennas, planar structures [4–8] in particular have been extensively investigated because of their attractive features such as simple structure, low profile, light weight, and ease of fabrication and integration. In [4], a printed planar ring-dipole microstrip fed antenna was designed to switch its radiation pattern in different directions depending on the state of six loaded PIN diode switches. A planar slotted bow-tie antenna with reconfigurable pattern properties was reported in [5]; the antenna consists of a pair of reconfigurable CPW-to-slot line transitions, a pair of Vivaldi-shaped radiating tapered slots, and four PIN diodes. The compact wideband antenna with alternate reflector and radiator presented in [6] achieves two directional radiation patterns by using short and open circuits (The maximum gain obtained is about 4.5？dBi for the RRC and about ？5？dBi for the LRC). In this paper, a planar printed dipole antenna with reconfigurable radiation performances operating at 2.56？GHz was designed. Depending on the states