Design of A Wideband Polarizer Integrated Antenna

Abstract

This report proposes a design of wideband polarizer integrated antenna operating at 30GHz which is close to the licensed bands. The proposed dielectric polarizer is consisted of air and dielectric slabs which have different dielectric constant and affect the travelling speeds of the components, EX and EY, of electric wave E radiated from the proposed antenna source placed under the polarizer. The difference of the travelling speeds lead to a phase difference between two components, EX and EY, and thus the linearly polarized incident wave can be transformed to circularly polarized wave. Besides, two antenna sources, patch antenna and planar dipole, are proposed with the polarizer. The simulated result shows that the gain of the proposed polarizer integrated patch antenna enhanced from 8.40dBi to 15.38dBic. However, the impedance bandwidth of the patch antenna is 2.83% from 29.57 to 30.43GHz which is not wide enough for the 5G wireless application. Thus, another antenna source, planar dipole fed by substrate-integrated-waveguide, is proposed. The simulation shows the proposed planar dipole with the polarizer achieve a wide impedance bandwidth of 22.5% from 27-33.75GHz, a high gain enhancement about 86.4% from 7.87dBi to 14.67dBic and a wide axial ratio which covers the 28GHz 5G spectrum bands. In short, this project is to propose a wideband antenna and polarizer which is able to enhance the gain of the antenna source and transform the linear polarization to circular polarization for antenna source.