High Performance Two-arm Antenna for Super Wideband Operation

A super wideband antenna is proposed to operate in the frequency band 2.2-22 GHz. The antenna has two planar arms printed on the opposite faces of a three-layer dielectric substrate. Each arm of the antenna is capacitively coupled to a circular ring near its end to increase the impedance matching bandwidth. The dielectric substrate is customized to fit the shape of the antenna arms and the parasitic elements to reduce the dielectric loss. The substrate material is composed of three layers. The upper and lower layers are Rogers RO3003[TM] of 0.13 mm thickness, and the middle layer is made of paper of 2.3 dielectric constant and 2.7mm thickness. The antenna is fed through a wide band impedance matching balun of a novel simple design. A prototype of the proposed antenna is fabricated to validate the simulation results. The experimental measurements are in good agreement with the simulation results, and both of them show that the antenna operates efficiently over the frequency band 2.2-22GHz with minimum radiation efficiency of 97% and maximum gain of 5.2dBi. The antenna has a bandwidth to dimension ratio (BDR) of 1755.