A high gain and simple-structured dielectric resonator antenna array with cylindrical rods and microstrip feeding

Abstract

A novel microstrip-fed dielectric rod array antenna with high end-fire gain is proposed. It has simple structure, comprising a group of cylindrical dielectric rods and a microstrip corporate feeding network, and is low in cost. A prototype 4 × 4 array working at 8.0 GHz is designed, fabricated and measured. Simulation and measurement results show the antenna has encouraging performances, e.g. an impedance bandwidth (|S11| < −10 dB) of 7.7%, an end-fire gain up to 20.3 dBi, side-lobes 13.5 dB below the main lobe, and linear polarization with the cross-polarization level less than −21 dB. In recent years, dielectric resonator antennas have become an attractive choice for many modern wire- less communications systems due to their advantages such as small size (1-4), wide impedance band- width (5-9),highradiationefficiency(10-12),etc.Butsofarin thelargenumbersofpreviousresearches, dielectric resonator antennas are commonly made of high permittivity materials (1-3) that are often ex- pensive. In many antennas, dielectric rods that act as radiation elements are with tapered (7-9) or other more complicated configurations (4,5), which bring forth difficulties for antennas' design and fabrica- tion. Some antennas are fed by a waveguide (3-5,8,10), an embedded probe (10), or a horn (13,14), which are not only difficult to be fabricated into modern devices but also may be bulky and expensive for a large array. In this work, a novel dielectric rod array antenna is presented. This antenna is the combination of a group of dielectric rods with a microstrip corporate feeding network. The dielectric rods are of simple cylindrical configuration, act as the array antenna's radiation elements and fabricated by using Teflon, which is a low-cost material, moreover is low-loss at microwave frequency and has a stable dielectric permittivity overa wide range of frequency. Moreover, this array antenna is fed by a microstrip corporate feeding network, and thus able to make full use of the accurate and low cost planar print techniques.