Four-port beam reconfigurable antenna array for pattern diversity system

Abstract

This study investigates a practical design for a switched beam planar antenna that can be implemented as a compact, low-cost switchable and/or reconfigurable beam antenna array. The antenna consists of a four-port antenna array, which is based on L-shaped quarter-wavelength slot antenna elements. This type of antenna array is a planar structure and its maximum directional radiation beam pattern presents in an azimuth plane covering 360 degrees. The antenna array operates based on the 'ON' or 'OFF' states of PIN diodes in each individual slot antenna element and the combined signals from the four-port output. Therefore by properly controlling the state of the PIN diodes, the antenna exposes its characteristics of switchable/reconfigurable beam patterns in the Phi-plane. To validate the proposed design, a small smart, switched-beam antenna operating at 2.7 GHz in multiple input-multiple output applications is simulated and fabricated.