High-Gain Metasurface in Polyimide On-Chip Antenna Based on CRLH-TL for Sub-Terahertz Integrated Circuits

Mohammad Alibakhshikenari; Bal S Virdee; Chan H See; Raed A Abd-Alhameed; Francisco Falcone; Ernesto Limiti

doi:10.1038/s41598-020-61099-8

High-Gain Metasurface in Polyimide On-Chip Antenna Based on CRLH-TL for Sub-Terahertz Integrated Circuits

Sci Rep. 2020 Mar 9;10(1):4298. doi: 10.1038/s41598-020-61099-8.

Authors

Mohammad Alibakhshikenari¹, Bal S Virdee², Chan H See^{3

4}, Raed A Abd-Alhameed⁵, Francisco Falcone⁶, Ernesto Limiti⁷

Affiliations

¹ Electronic Engineering Department, University of Rome "Tor Vergata", Via del Politecnico 1, 00133, Rome, Italy. alibakhshikenari@ing.uniroma2.it.
² London Metropolitan University, Center for Communications Technology & Mathematics, School of Computing & Digital Media, London, N7 8DB, UK.
³ School of Engineering & the Built Environment, Edinburgh Napier University, 10 Colinton Road, Edinburgh, EH10 5DT, UK.
⁴ School of Engineering, University of Bolton, Deane Road, Bolton, BL3 5AB, UK.
⁵ School of Electrical Engineering & Computer Science, University of Bradford, Bradford, BD7 1DP, UK.
⁶ Electrical and Electronic Engineering Department, Public University of Navarre, 31006, Pamplona, Spain.
⁷ Electronic Engineering Department, University of Rome "Tor Vergata", Via del Politecnico 1, 00133, Rome, Italy.

Abstract

This paper presents a novel on-chip antenna using standard CMOS-technology based on metasurface implemented on two-layers polyimide substrates with a thickness of 500 μm. The aluminium ground-plane with thickness of 3 μm is sandwiched between the two-layers. Concentric dielectric-rings are etched in the ground-plane under the radiation patches implemented on the top-layer. The radiation patches comprise concentric metal-rings that are arranged in a 3 × 3 matrix. The antennas are excited by coupling electromagnetic energy through the gaps of the concentric dielectric-rings in the ground-plane using a microstrip feedline created on the bottom polyimide-layer. The open-ended feedline is split in three-branches that are aligned under the radiation elements to couple the maximum energy. In this structure, the concentric metal-rings essentially act as series left-handed capacitances C_L that extend the effective aperture area of the antenna without affecting its dimensions, and the concentric dielectric rings etched in the ground-plane act as shunt left-handed inductors L_L, which suppress the surface-waves and reduce the substrates losses that leads to improved bandwidth and radiation properties. The overall structure behaves like a metasurface that is shown to exhibit a very large bandwidth of 0.350-0.385 THz with an average radiation gain and efficiency of 8.15dBi and 65.71%, respectively. It has dimensions of 6 × 6 × 1 mm³ that makes it suitable for on-chip implementation.