A High-Temperature and Frequency-Reconfigurable Multilayer Frequency Selective Surface Using Liquid Metal

Peng Li,Zemin Ren,Weigang Liu,Wenju Meng,Liwei Song

doi:10.1109/access.2022.3144509

Peng Li, Zemin Ren + Show 3 more

Open Access

https://doi.org/10.1109/access.2022.3144509

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Abstract

A high-temperature and frequency-reconfigurable multilayer frequency selective surface (FSS) based on liquid metal is proposed in this work. After construction of a multilayer dielectric cavity with specific dielectric-shaped pillars and the injection of liquid metal (EGaIn) into each layer of the cavity, the liquid metal and dielectric pillars form a slot-type bandpass FSS, and frequency reconfiguration is realized by switching the injection layer. A prototype of the proposed FSS was designed, fabricated and measured. The measured results validated the design well. The good conductivity and fluidity of the liquid metal are utilized to realize the reconfigurable electromagnetic performance of the proposed FSS. This works in the C-band (5 GHz) and Ku band (13 GHz) and has a frequency switching time between 13.1 to 14.2 s. Moreover, due to the good thermal conductivity of liquid metal, the flowing liquid metal can take away heat, and the multilayer FSS can work as cooling plate. The heat transfer performance was investigated by numerical simulations. A 1000 ° plane heat source was set on the bottom surface of the double-layer FSS. The average temperature on the top surface was 62.2 °, when the liquid metal fluid in the FSS had a speed of 1 m/s. The proposed multilayer FSS has strong potential for applications in some special application fields involving stealth and hypersonic aircraft.

Highlights

A radome is an indispensable piece of equipment for airborne electronic systems, such as detection, navigation, communication and identification systems [1], [2]
The frequency selective surface (FSS) is widely used in the fields of hybrid radomes [7], circuit analog absorbers [8], zigzag linear polarizers [9], etc., among which the most representative is the application to modern military technology such as stealth aircraft [10], [11]
In 2009, scientists found that the liquid metal eutectic gallium-indium (EGaIn) is nontoxic and has all the electromagnetic characteristics needed by an antenna

Summary

INTRODUCTION

A radome is an indispensable piece of equipment for airborne electronic systems, such as detection, navigation, communication and identification systems [1], [2]. P. Li et al.: High-Temperature and Frequency-Reconfigurable Multilayer FSS Using Liquid Metal bandpass FSS with an adjustable passband by using a varactor diode [16]. Li et al.: High-Temperature and Frequency-Reconfigurable Multilayer FSS Using Liquid Metal bandpass FSS with an adjustable passband by using a varactor diode [16] The former is a mechanically adjustable FSS, and the latter is an electronically controlled FSS. In 2009, scientists found that the liquid metal eutectic gallium-indium (EGaIn) is nontoxic and has all the electromagnetic characteristics needed by an antenna It is being researched as a promising new material for reconfigurable antennas [23]. This work proposes a reconfigurable bandpass slot-type multilayer liquid metal FSS that has a high heat transfer capacity. The proposed multilayer FSS has good performance in both frequency selection and heat transfer and has strong potential for applications in specific scenarios; e.g., stealth and hypersonic aircraft

MULTILAYER FSS ELEMENT DESIGN

PARAMETER OPTIMIZATION AND PROTOTYPE FABRICATION

MEASUREMENT AND DISCUSSION

THERMAL ANALYSIS

Findings

CONCLUSION