An Efficient Hemispherical Antenna Design for Wideband Applications

Abstract: Liquid antennas are the type of antenna which utilize fluid to transmit and receive radio signals. Two types of liquid antennas are widely investigated: liquid metal antennas and water-based liquid antennas. As a special type of liquid antennas, water antennas are one of the most popular. They have attractive features such as: a) low-cost and readily accessible; b) compact size - water is a high permittivity material. This paper describes a hemispherical antenna made of pure water. The water hemispherical antenna is realized by replacing the metallic arm of a conventional hemispherical antenna with a plastic tube of circular cross section and filled with pure water. The axially symmetric TM01 mode is excited along the water arm and accounts for the wave propagation and radiation. Circular polarization is achieved by choosing a proper dimension of the water helix. The hemispherical antenna exhibits polarization- reconfigurable capability over a wide frequency band. The proposed antenna is designed and simulated using HFSS software design tool by forming virtual radiation.

Keywords: Hemispherical antenna, polarization reconfigurable antenna, water antenna.