A Half-Biconical Antenna With Enhanced Unidirectional Radiation Using Irregular Dielectric Lens

Aimed to resolve the beam splitting in high frequency, an improved half-biconical antenna using an irregular dielectric lens is designed. Based on the conventional shark antenna, the metal reflector on the back is removed, and an optimized irregular dielectric lens is loaded in front of the antenna to form a plane wave. In this way, the radiation beamwidth becomes more concentrated and the boresight gain in the middle and high-frequency bands is improved. To validate the design, a prototype is fabricated and tested. Measured results show that the impedance bandwidth reaches 1.02–31 GHz for VSWR < 2. In the impedance bandwidth, stable directional radiation is achieved in both E- and H-planes.