A Wideband Slotted Spherical Waveguide Antenna Based on Multi-Mode Concept

Abstract

A wideband slotted spherical waveguide antenna based on the multi-mode concept is presented. The proposed design starts from a metallized spherical cavity fed by a rectangular waveguide. Then, two groups of slots are symmetrically cut on the shell. By suitably choosing the slot dimensions and locations, four radiation modes can be excited in a single radiator and merged with each other, resulting in a wideband radiation characteristic. To verify this, a prototype is designed and fabricated using stereolithography apparatus to achieve a light weight. As the measured fractional bandwidth (FBW) of the proposed antenna can be increased to 70.1% while maintaining stable radiation patterns and high gain, a simple and effective design of wideband slotted waveguide antennas with good radiation characteristics can be validated.

An Efficient Fast and Convergence-Controlled Algorithm for Sidelobes Simultaneous Reduction (SSR) and Spatial Filtering

“…This necessitates the requirement of powerful spatial filtering techniques especially for real time communications scenarios which require rapid and adaptive manipulation of the received signals. One of the most spatial filtering applications is sidelobe levels (SLL) reduction in the radiation pattern of the array, which greatly improves the quality of the received signal especially in rich interference environments [6][7][8][9][10][11][12][13]. Almost all communication systems require SLL control including radar, sonar, satellite and even space communications [14].…”