Integrated-Circuit Enabled Adaptive Metasurface Absorber With Independent Tuning of Orthogonal Polarization Planes

Kypros M Kossifos,Julius Georgiou,Marco A Antoniades

doi:10.1109/access.2020.2977852

Kypros M Kossifos, Julius Georgiou + Show 1 more

Open Access

https://doi.org/10.1109/access.2020.2977852

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Abstract

A customized integrated circuit (IC) is presented that is designed specifically for implementing complex-impedance metasurface loading elements. This IC enables innovative metasurface designs that target absorption applications. Through targeted electronic and electromagnetic co-design, we propose an innovative metasurface unit cell to implement a tunable metasurface absorber. We demonstrate the proposed loading element performance range through a fabricated custom IC. Experimental measurements of the fabricated loading element circuit in a 180 nm CMOS technology are used in an electromagnetic simulator to demonstrate tunable perfect absorption at normal and oblique angles of incidence for both transverse electric (TE) and transverse magnetic (TM) polarizations. With four of the proposed loading elements, realized on a custom IC, the metasurface absorber is shown to control independently and simultaneously the absorption of both TE and TM polarizations.

Highlights

Thin, two dimensional metamaterials, known as metasurfaces (MSFs), are composite materials that have been shown to demonstrate many novel properties such as anomalous reflection [1], [2], perfect absorption [3], [4] and nonlinear reflection [5]
In this work, a complex impedance metasurface loading element was implemented on a custom designed integrated circuit
The MSF loading elements (LEs) was designed in a 180 nm technology that is commercially available; it occupies an area of 520 μm × 640 μm and draws negligible bias current, in the order of pAs, enabling large metasurfaces to be created

Summary

INTRODUCTION

Thin, two dimensional metamaterials, known as metasurfaces (MSFs), are composite materials that have been shown to demonstrate many novel properties such as anomalous reflection [1], [2], perfect absorption [3], [4] and nonlinear reflection [5]. The approach in [21] and [22] uses only reactively tunable commercial off the shelf components (CoTS) and large distributed elements to create a high impedance in order to bias the MSF loading elements (LEs) from beneath the ground plane without affecting the RF signal. The proposed MSF design operates using realistic component properties We demonstrate this in simulations, using measured results taken from our proposed tunable complex impedance LE that was implemented in a commercially-available 180 nm CMOS technology. The on-chip DC block capacitor does not have ideal behavior, primarily due to the capacitance of the bottom plate to the substrate ground For this reason, each element in the schematic will affect the total impedance that is seen by the one-port network.

DESIGN OF THE ON-CHIP LOADING ELEMENT COMPONENTS

METASURFACE ABSORBER

CONCLUSION