Design and Analysis of a Coupling-Fed Printed Dipole Array Antenna With High Gain and Omnidirectivity

Abstract

A printed omnidirectional dipole array antenna with a radiated load is proposed and analyzed, which is fed by a coplanar waveguide. Flying lines and via-holes are used to connect dipoles to achieve a balanced feed. Simulated results by CST microwave studio® indicate that the operating band is 4.6 to 4.9 GHz with its reflection coefficient less than −10 dB. The omnidirectional gain in this band is higher than 4.23 dB and the antenna size is only $103.4 \text {mm}\times 12.6 \text {mm}\times 1.5 \text {mm}$ . As a result, its gain per wavelength can reach a high value of 3.1 dB/ $\lambda $ at 4.7 GHz, which is conducive to antenna miniaturization and batch production. In order to effectively decrease the outer surface current on the coaxial feeder outer conductor, a printed choke is introduced, so that the antenna performance would not be affected by an even longer coaxial line. The bandwidth and gain are improved achieving 4.63–5.45GHz and 5.8dB, respectively. There is a broad application of the designed antenna for it not only can be used independently, but also can be integrated on the printed circuit board.