A Wideband High-Gain Dipole with Impedance and Field Control Structures

Abstract

Dipoles are favorable in various applications because of their simple and light structure. However, narrow bandwidths and low gain values limit their usage in wideband and long-range systems. To solve this problem, this paper presents a new method to achieve wideband high-gain for dipoles with embedded double-sleeve and a bathtub-shaped cavity. The double-sleeve adjusts the dipole’s impedance and enforces wideband matching from 4.8 GHz to 9.4 GHz. Furthermore, the bathtub-shaped cavity reshapes the antenna’s radiation field and elevates the antenna’s boresight gain to be above 10 dBi in the bandwidth of 5 GHz to 9.4 GHz, which is a 7.75 dBi improvement over the 2.15 dBi gain of conventional dipoles. The combination of the two structures creates a wideband high-gain dipole that features an average simulated boresight realized gain of 11.8 dBi in the impedance bandwidth of 64.8%. Thus, the new antenna can work efficiently in wideband and long-range systems because of its enhanced bandwidth and gain performances.