Polarization insensitive non-interleaved frequency multiplexed dual-band Terahertz coding metasurface for independent control of reflected waves

Shahid Iqbal; Ahsan Noor; Naeem Ullah; Yasir Saifullah; Shehzad Ahmed; Muhammad Shemyal Nisar; Sai-Wai Wong

doi:10.1038/s41598-024-71910-5

Polarization insensitive non-interleaved frequency multiplexed dual-band Terahertz coding metasurface for independent control of reflected waves

Sci Rep. 2024 Sep 11;14(1):21199. doi: 10.1038/s41598-024-71910-5.

Authors

Shahid Iqbal¹, Ahsan Noor², Naeem Ullah³, Yasir Saifullah¹, Shehzad Ahmed³, Muhammad Shemyal Nisar⁴, Sai-Wai Wong⁵

Affiliations

¹ State Key Laboratory of Radio Frequency Heterogenous Integration, Guangdong Engineering Research Centre of Base Station Antennas, Shenzhen Key Laboratory of Antennas and Propagation, College of Electronics and Information Engineering, Shenzhen University, Shenzhen, 518060, China.
² Electrical and Electronics Engineering, Southern University of Science and Technology, Shenzhen, 518055, China.
³ College of Physics and Optoelectronics engineering, Shenzhen University, Shenzhen, 518055, China.
⁴ Sino-British College, University of Shanghai for Science and Technology, Shanghai, 200093, China.
⁵ State Key Laboratory of Radio Frequency Heterogenous Integration, Guangdong Engineering Research Centre of Base Station Antennas, Shenzhen Key Laboratory of Antennas and Propagation, College of Electronics and Information Engineering, Shenzhen University, Shenzhen, 518060, China. wongsaiwai@ieee.org.

Abstract

Independent control of electromagnetic (EM) waves by metasurfaces for multiple tasks are highly desired and is the recent hot topic of research. In this work we contribute a polarization insensitive frequency multiplexed 2-bit coding metasurface to control the Terahertz (THz) waves in the two operating bands independently. In this regard, as a first step a cascaded meta-atom composed of square rings and/or square metallic patches separated by two polyimide substrates is designed and optimized that provides sixteen independent distinct discrete phases in the reflection geometry. These meta-atoms are then distributed with distinct coding sequences in the two-dimensional spatial plane to realize various bi-functional metasurfaces. As a proof of the concept various full structures are designed and simulated to realize a series of bi-functionalities including anomalous reflection/beam shaping, beam shaping/anomalous reflection, beam deflection/Orbital angular momentum (OAM) beam generation with distinct modes and propagating wave to surface wave (PW-SW) conversion/PW beam manipulation in the lower and higher THz bands, respectively. All the simulation results are in excellent agreement with their theoretical equivalents. We envision that the proposed meta-designs have potential applications for the multi-spectral control of EM waves in THz band. The idea can be further extended to design frequency dependent tri-functional and multi-functional THz meta-devices.

Keywords: Digital coding metasurface; Dual-band; Frequency multiplexed; Multi-mode OAM beams; Polarization insensitive; Propagating waves controlling; Surface waves generation and controlling.

Abstract

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