Linearly Polarized SIW Horn Antenna Integrated with MM for Gain Enhancement and Polarization Conversion

A planar substrate integrated waveguide horn (SIWH) antenna is introduced and optimized to compete with circuits on-chip for 5G communications. The performance parameters of the linearly polarized (LP) planar SIWH antenna are investigated. It introduces bandwidth of 270 MHz with maximum gain of 5.7 dBi. The gain of the LP SIWH antenna is improved by inserting perforated metamaterial (MM) unit-cell elements in the structure. The distributions and the number of perforated unit-cell elements are optimized for maximum gain. A further gain enhancement is accomplished by a rectangular or cylindrical dielectric lens extended in front of the horn aperture. An improvement in the bandwidth of 670 MHz with 10.47 dBi gain is accomplished using the cylindrical dielectric lens. A planar semi-helix MM polarization converter is placed on the horn aperture to convert LP to circular polarization (CP). The dimensions and the orientation of the semi-helix MM polarization converter is optimized for maximum CP bandwidth.