A Compact Ultra-Wideband Multibeam Antenna System

A compact UWB (6-18 GHz) multibeam antenna system is proposed. Design procedures comprising of ridged coaxial waveguide, radome with lens properties, and biconical antenna are presented. A novel UWB feed network consisting of a ridged coaxial waveguide with eight inputs has been designed and optimized to achieve minimum reflections as well as desired radiation pattern over the frequency range of operation. The radiating element is a biconical antenna, redesigned and optimized to meet the requirements for radiation characteristics. Another notable improvement made by our design is to employ a radome, which not only enhances the mechanical stability of the biconical antenna and protects the structure, but also it acts as a lens that improves the directivity of the radiating element. Extensive optimization procedures have been applied to all parts of the antenna system to achieve the desired performance. The whole system has been simulated using HFSS full-wave simulator. The measurement results of the fabricated system are in good agreement with simulations.