Graphene Based Tunable THz Micro-Strip Antenna Using Piezoelectric Substrate

In this work, Tunable Graphene based Micro-strip Patch Antenna is realized using chemical potential of Graphene and a piezoelectric substrate. Initially, Micro strip patch antenna is designed with Graphene as a conductor, Rochelle Salt (RS) Crystal as a dielectric substrate at 3.3 THz with return loss of 18.5 dB. Tunable triple band operation is obtained by fixing the chemical potential at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0 \text{eV}, 0.05 \mathrm{e} \mathrm{V}$</tex>, and 0.5 eV with S 11 values of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$-24 \text{dB},-12 \text{dB},-21 \text{dB}$</tex>, respectively at the resonant frequencies of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2.9 \text{THz}, 3.35 \text{THz}$</tex> and 3.84 THz. Peak gain of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.3 \text{dB}, 1.2 \text{dB}$</tex>, and 5 dB are achieved for the chemical potential of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0 \text{eV}, 0.05 \mathrm{e} \mathrm{V}$</tex>, and 0.5 eV respectively. Further, by using the piezoelectric property of RS crystal, tunability is investigated. When DC voltage is applied on both the sides of Rochelle Salt Crystal, due to its piezo electric property, its height can be varied, which in turn, results in multiple resonant frequencies. At a substrate height of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{3 0. 0 2} \mu \mathrm{m}$</tex>, triple band is obtained with the return loss of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$-18.51 \text{dB},-22.4$</tex> dB, and −10.44 dB at 2.55 THz, 3.29 THz, and 3.83 THz respectively. Moreover, Maximum gain of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0 \text{dB}, 4 \text{dB}$</tex>, and 5.2 dB are also obtained for the substrate height of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{3 0. 0 0 4} \boldsymbol{\mu} \mathbf{m}, \mathbf{3 0. 0 1} \boldsymbol{\mu} \mathbf{m}$</tex>, and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$30.02 \mu \mathrm{m}$</tex> respectively.