Now showing 1 - 2 of 2
  • Publication
    Electrically tunable Left-Handed textile metamaterial for microwave applications
    ( 2021)
    Kabir Hossain
    ;
    ; ;
    Ping Jack Soh
    ;
    Mohd Haizal Jamaluddin
    ;
    Samir Salem Al-Bawri
    ;
    ;
    R. Badlishah, Ahmad
    ;
    ; ;
    Nitin Saluja
    An electrically tunable, textile-based metamaterial (MTM) is presented in this work. The proposed MTM unit cell consists of a decagonal-shaped split-ring resonator and a slotted ground plane integrated with RF varactor diodes. The characteristics of the proposed MTM were first studied independently using a single unit cell, prior to different array combinations consisting of 1 × 2, 2 × 1, and 2 × 2 unit cells. Experimental validation was conducted for the fabricated 2 × 2 unit cell array format. The proposed tunable MTM array exhibits tunable left-handed characteristics for both simulation and measurement from 2.71 to 5.51 GHz and provides a tunable transmission coefficient of the MTM. Besides the left-handed properties within the frequency of interest (from 1 to 15 GHz), the proposed MTM also exhibits negative permittivity and permeability from 8.54 to 10.82 GHz and from 10.6 to 13.78 GHz, respectively. The proposed tunable MTM could operate in a dynamic mode using a feedback system for different microwave wearable applications.
  • Publication
    Radiation pattern reconfigurable MIMO Antenna with practical DC bias network
    ( 2022-01-01)
    Jaya Bharath A/L Gopalakrishnan
    ;
    Thennarasan A/L Sabapathy
    ;
    ; ;
    Muhammad Ramlee Kamarudin
    ;
    Soh Ping Jack
    This paper presents a radiation pattern reconfigurable (RPR) based multiple-input multiple-output (MIMO) antenna. The proposed antenna operates at 3.5 GHz for all switching conditions with S21 results of less than -20 dB. This work specifically focuses on implementing a practical DC bias network for the previously proposed RPR-MIMO antenna. The DC bias design is crucial where the tilt angle is slightly affected. This could be due to the isolation loss and insertion loss provided by the actual switch; and the DC bias lines that were constructed using a few DC blocking capacitors and RF chokes. Finally, a comprehensive analysis was carried out to examine the beam steering performance of the antenna when implemented with the DC bias network.
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