A Reconfigurable Switched-Beam System With Single-/Dual-Lobe and Wide-Beam Radiation Patterns

This article reports a flexible switched-beam system that can generate single-lobe, dual-lobe, and wide-beam radiation patterns. It consists of a three-element antenna array and a reconfigurable feeding network. Based on the rigorous calculations of the array factor (AF), the required power divisions and phase differences of the feeding network can be obtained for different kinds of radiation patterns. The proposed feeding network is constructed by a 3-bit reconfigurable power divider (RPD) and a 3 ×3 Nolen matrix (NM). The 3-bit power divider operates in seven modes, providing three single-feed, three dual-feed, and one triple-feed states for the NM. The NM is designed to output the required excitations for the antenna array with different feeds. Three log-periodic bowtie dipoles with wide-beamwidth radiation construct the antenna array. A prototype of the proposed flexible switched-beam system operating at 5 GHz is designed, fabricated, and measured for demonstration. By controlling the codes of the biasing voltages of the p-i-n diodes, the system radiates five single-lobe beams at 54°, 75°, 90°, 102°, 123°, a dual-lobe beam at 90°± 45°, and a wide beam from 39° to 132°.