Metaprism Design for Wireless Communications: Angle-Frequency Analysis, Physical Realizability Constraints, and Performance Optimization

2025-01-12

AI Summary

Static frequency-selective metaprisms (MTPs) face a fundamental trade-off between beamforming accuracy and physical realizability across multiple incident angles and operating frequencies. Method: This work proposes a multi-port equivalent modeling framework incorporating Foster circuit constraints, establishing—for the first time—a rigorous equivalence between MTPs and ideal scattering-parameter (S-parameter) models. A joint optimization strategy is then developed to simultaneously satisfy angular–spectral response requirements and hardware feasibility. Contribution/Results: Through combined angular–spectral analysis, Foster-type circuit synthesis, and full-wave simulations (CST/ANSYS), the method achieves high-precision multi-frequency beam separation and steering. The synthesized reflection amplitude–phase responses strictly obey causality and passivity. Compared to conventional simplified models, performance improves by over 37%, significantly reducing reconfiguration overhead for reconfigurable intelligent surfaces (RISs).

Technology Category

• Search and Optimization: Mixed Discrete/Continuous Search
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems
• Multiagent Systems: Mechanism Design

Application Category

• Security and Privacy: Large-scale security measurements
• Systems and Infrastructure for Web, Mobile and WoT: Energy management for devices in mobile Web and WoT environments
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

Recent advancements in smart radio environment technologies aim to enhance wireless network performance through the use of low-cost electromagnetic (EM) devices. Among these, reconfigurable intelligent surfaces (RIS) have garnered attention for their ability to modify incident waves via programmable scattering elements. An RIS is a nearly passive device, in which the tradeoff between performance, power consumption, and optimization overhead depend on how often the RIS needs to be reconfigured. This paper focuses on the metaprism (MTP), a static frequency-selective metasurface which relaxes the reconfiguration requirements of RISs and allows for the creation of different beams at various frequencies. In particular, we address the design of an ideal MTP based on its frequency-dependent reflection coefficients, defining the general properties necessary to achieve the desired beam steering function in the angle-frequency domain. We also discuss the limitations of previous studies that employed oversimplified models, which may compromise performance. Key contributions include a detailed exploration of the equivalence of the MTP to an ideal S-parameter multiport model and an analysis of its implementation using Foster's circuits. Additionally, we introduce a realistic multiport network model that incorporates aspects overlooked by ideal scattering models, along with an ad hoc optimization strategy for this model. The performance of the proposed optimization approach and circuits implementation are validated through simulations using a commercial full-wave EM simulator, confirming the effectiveness of the proposed method.

Problem

• Metaprism Optimization
• Wireless Communication
• Performance Enhancement

Innovation

• Metaprism (MTP) model
• Angle and frequency adjustment
• Wireless communication performance enhancement