Low-Profile Automotive Antenna for Omnidirectional Vertical Polarized Signal Reception

Abstract

A low-profile antenna is designed for a WiBro vertical polarized signal. The proposed antenna is packaged and installed on the roof of a vehicle. The low-profile configuration is inspired from a zero-phase constant that realizes a horizontal magnetic loop current distribution equivalent to a vertical electric current distribution. With the proposed antenna, a wide bandwidth is achieved by overcoming the narrow bandwidth characteristics of an antenna with a zero-phase constant. The antenna was designed using a large conductive plate to simulate the vehicle roof in the electromagnetic simulation, thereby dramatically reducing simulation time. The results are comparable to the experimental results of an antenna on a vehicle's roof. The unpackaged and packaged antennas' radiation patterns are first measured in an anechoic chamber. Azimuth patterns are measured by installing the packaged antenna on the vehicle's roof. Simulations agree with experimental data where the vertically polarized signal is successfully received with a reasonable gain and efficiency in a WiBro band.