Comparison of Flexible Substrates for Microstrip Antenna Design for ISM Band

In this paper was made a comparison between three microstrip antennas with different flexible substrates at 2.4 GHz. These substrates are Polyethylene Terephthalate (PET), Thermoplastic Polyurethane (TPU), and a semi-flexible substrate composed by Polyethylene Terephthalate Glycolmodified (PETG). The measurements were focused on parameters of reflection coefficient (S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</inf>), VSWR, bandwidth (BW), and impedance (Z<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">L</inf>). The three models were designed in Ansys HFSS, and for the construction we used 3D prints and copper tape. For S<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">11</inf>, PETG had an improvement of -23.36 dB, and-19.88 dB, in comparison with PET and TPU respectively. For bandwidth, TPU had an improvement of 86,23 MHz and 88 MHz in comparison with PET and PETG respectively. Finally, for VSWR, PETG has an improvement of 0.44 and 0.22 in comparison with PET and TPU. This means that PETG as a semi-flexible material shows better performance in the global scenario of analysis.