[Paper Review] Intelligent Radome Design Using Multilayer Metamaterial Structures to Realize Energy Isolation and Asymmetric Propagation of Electromagnetic Wave

Jing Yuan, Kong Xiang+2 more|arXiv (Cornell University)|Mar 5, 2020

Advanced Antenna and Metasurface Technologies27 references31 citations

TL;DR

This paper proposes an intelligent radome using multilayer metamaterial structures that enable asymmetric electromagnetic wave propagation and high-power electromagnetic wave (HPEMW) shielding through active control of PIN diodes. By integrating a broadband polarization converter (PC) and an active frequency selective rasorber (AFSR), the radome transmits low-power signals asymmetrically while absorbing HPEMWs above 1.8 GHz, achieving <1 dB insertion loss in the 3.48–3.58 GHz band and over 90% absorption from 2.3–4.4 GHz when diodes are triggered.

ABSTRACT

An intelligent radome utilizing composite metamaterial structures is presented and investigated in this article, which can realize energy isolation and asymmetric propagation of electromagnetic (EM) wave self-adaptively by controlling states of PIN diodes. The whole structure mainly consists of a broadband polarization-sensitive polarization converter (PC) and an active frequency selective rasorber (AFSR) switching between a transmission mode and absorption mode which is used as an energy-selective surface (ESS). Among them, the function of the PC is to make the EM waves transmit asymmetrically, and the purpose of AFSR is to make the high-power waves be reflected or absorbed, which depends on the polarization type of the wave. Thus, the radome can realize both asymmetric propagations of EM wave and electromagnetic shielding. The equivalent circuit models (ECM) and parametric studies are considered to explain the physical operating mechanism of PC and AFSR. The fabricated structure with 7*7 unit cells is experimentally demonstrated and the measured results agree with simulated results well. Considering the distinctive characteristic of self-actuation, the presented concept has the potential application in electromagnetic stealth and HPEMWs shielding to protect communication devices.

Motivation & Objective

• To address the challenge of protecting communication devices from high-power electromagnetic wave (HPEMW) attacks while maintaining normal signal transmission.
• To overcome the limitations of conventional radomes that cannot simultaneously achieve asymmetric wave propagation and active HPEMW shielding.
• To design a self-actuated, intelligent radome that dynamically switches between transparent and absorptive states based on signal power.
• To integrate polarization control and energy-selective response in a single multilayer metamaterial structure for enhanced electromagnetic functionality.
• To validate the design through equivalent circuit modeling (ECM), full-wave simulation (CST), and experimental measurement on a 7×7 unit cell prototype.

Proposed method

• The radome integrates a broadband polarization converter (PC) made of three functional layers and two air layers, enabling asymmetric transmission of x- and y-polarized waves depending on incident direction.
• An active frequency selective rasorber (AFSR) with embedded PIN diodes acts as an energy-selective surface (ESS), switching between transmission (diodes OFF) and absorption (diodes ON) modes based on signal power.
• The PC uses orthogonal metal strips and a 45° rotated elliptical structure to create a Fabry-Pérot cavity and resonance for broadband polarization conversion.
• The AFSR employs slot arrays and lumped elements (resistors, inductors, capacitors) to form an equivalent RLC circuit model (ECM), enabling tunable absorption at 1.8–4.4 GHz when diodes are forward-biased.
• A parallel biasing configuration is used to simulate HPEMW excitation and trigger diodes without external coupling.
• Full-wave simulations (CST) and experimental measurements in an anechoic chamber validate the design, with S-parameters compared between simulation and measurement.

Experimental results

Research questions

• RQ1 Can a multilayer metamaterial radome simultaneously achieve asymmetric electromagnetic wave propagation and active shielding of high-power electromagnetic waves?
• RQ2 How can polarization conversion and power-dependent switching between transmission and absorption be achieved in a single integrated structure?
• RQ3 What is the physical operating mechanism behind the broadband asymmetric transmission and tunable absorption in the proposed PC and AFSR?
• RQ4 To what extent does the equivalent circuit model (ECM) accurately predict the behavior of the PC and AFSR under different diode states?
• RQ5 How do fabrication tolerances and component inaccuracies affect the measured performance compared to simulation?

Key findings

• The radome achieves asymmetric transmission with insertion loss below 1 dB across a 100 MHz bandwidth (3.48–3.58 GHz) when PIN diodes are OFF.
• When PIN diodes are ON, the structure absorbs over 90% of incident energy from 2.3 GHz to 4.4 GHz, effectively shielding HPEMWs.
• Measured insertion loss is 2.6 dB at the center frequency (3.54 GHz) when diodes are OFF, with a 0.3 GHz frequency shift compared to simulation.
• The AFSR achieves a minimum insertion loss of 0.6 dB in the passband when diodes are in cutoff (OFF state), confirming effective signal transmission.
• The measured and simulated S-parameters show good agreement, validating the design and ECM-based analysis.
• The prototype demonstrates self-actuated functionality: low-power signals pass asymmetrically, while high-power waves are absorbed, enabling dual functionality in a single device.