Design and Analysis of a Helical Antenna Operating in Normal-Mode at 1.8 GHz with Cylindrical Side Walls Enabling Polarization Change and Gain Enhancement Features

Abstract

In this paper, a helical antenna operating in normal mode at 1.8 GHz on a ground plane with cylindrical metallic side walls is presented. In the designed structure the side walls are placed on the ground plane at a certain distance from the antenna with a specific height in determined directions occupying certain angles. With simulations resonance behavior and far-field radiation patterns of the antenna were investigated. Results show that adding side walls increases the antenna gain by approximately 2.7 dBi, while the resonance behavior remains almost the same. Also, co- and cross-polarization levels change depending on the side walls. To verify simulation results, two of the designed antennas were manufactured and a setup was constructed. By using a network analyzer resonance behavior of the antennas and their coupling were measured. Measurement results demonstrate gain enhancement of the antenna with addition of the side walls and they are in good agreement with the simulation results. The findings show that adding cylindrical side walls is an effective and low-cost approach to improve the performance of helical antennas without structural changes, making these antennas suitable for wireless communication applications.