Synthesis, Design, and Implementation of Wideband 3-D Transmitting/Reflecting Pattern Manipulation Structures

This article presents the synthesis, design, and implementation of wideband 3-D transmitting/reflecting pattern manipulation structures (PMSs). Firstly, the design of the basic element is systematically investigated. Based on our established equivalent transmission line model, the basic element is synthesized and designed with a simple 3-D structure to effectively convert spatial waves into guided waves under prescribed performances. Then, two basic elements are antipodally placed and electrically connected by a true-time delay line, forming a transmitting element. In this way, the spatial wave can nearly perfectly propagate through the transmitting element with a manipulated transmission phase. Employing this type of element, a wideband 3-D transmitting PMS is designed for the directing angle of ( θ_t = 40°, φ_t = 90°). In addition, the reflecting element is constructed by introducing the short-circuited true-time delay line in a basic element. After that, a wideband 3-D reflecting PMS is accomplished for a pointing angle of ( θ_r = 40°, φ_r = 90°). Finally, these two PMSs are implemented with fabrication and testing. Measurements agree well with simulations, proving our proposed design concept. Within the operating bandwidth of 64.9% in fraction (6.5-12.75GHz) for the transmitting PMS, the simulated and measured average efficiencies are higher than 82.5% and 77.8%, respectively. For the reflecting PMS, an operating bandwidth of 70.1% in fraction (6.25-13.0GHz) is realized, where the in-band average efficiencies for simulation and measurement reach 82.5% and 77.4%, respectively. Therefore, the proposed wideband 3-D transmitting/reflecting PMS has been evidently confirmed and can be potentially employed as a promising selection to manipulate the radio wave for future networks.

3-D structures, synthesis and design, transmitting/reflecting pattern manipulation structures, wide bandwidth.