On the Design and Simulation of Antennas on Ultra-thin Flexible Substrates
Keywords:CST, flexible antenna, HFSS, substrate, ultra-thin
Flexible wireless systems are rapidly evolving in a wide spectrum of applications such as medical, entertainment and sport facilities. The aim of this paper is to investigate whether the ultra-thin substrates along with their permittivity are essential for the initial design stage of a flexible antenna, which is a key element of any wireless system, or it is merely a supporting structure. Three state-of-the-art simulation tools are used to evaluate the scattering parameter, S11 which are then compared against precise measurements conducted inside an anechoic chamber. These methods are the Finite Integration Technique (FIT) based Time Domain Solver (TDS) and the Finite-Element Method (FEM) based Frequency Domain Solver (FDS) of CST Microwave Technology and the (FEM) based HFSS of ANSYS. This paper attempts to provide an answer as to whether the substrate and other geometrically small features such as the feeding structure should be sufficiently discretized or else conventional default adaptive meshing should be enough. Three different flexible antennas with two fabrication techniques and feed lines have been used in the simulations and measurements.
H. R. Raad, A. I. Abbosh, H. M. Al-Rizzo, and D. G. Rucker, “Flexible and compact AMC based antenna for telemedicine applications,” IEEE Trans. Antennas Propag., vol. 61, no. 2, pp. 524-531, 2013.
J. E. Ruyle, A. Moreno, and J. T. Bernhard, “Placement-insensitive flexible RFID antenna for ‘peel-and-stick’ applications,” IET Microw. Antennas & Propag., vol. 11, no. 3, pp. 433-441, 2017.
P. Rocca and A. F. Morabito, “Optimal synthesis of reconfigurable planar arrays with simplified architectures for monopulse radar applications,” IEEE Trans. Antennas Propag., vol. 63, no. 3, pp. 1048-1058, 2015.
S. Kumar, V. Bhat, K. J. Vinoy, and V. Santhanam, “Using an office inkjet printer to define the formation of copper films on paper,” IEEE Trans. Nanotechnol., vol. 13, no. 1, pp. 160-164, 2014.
H. R. Khaleel, H. M. Al-Rizzo, D. G. Rucker, and S. Mohan, “A compact polyimide-based UWB antenna for flexible electronics,” IEEE Antennas Wirel. Propag. Lett., vol. 11, pp. 564-567, 2012.
S. Hong, S. H. Kang, Y. Kim, and C. W. Jung, “Transparent and flexible antenna for wearable glasses applications,” IEEE Trans. Antennas Propag., vol. 64, no. 7, pp. 2797-2804, 2016.
Z. Hamouda, et al., “Dual-band elliptical planar conductive polymer antenna printed on a flexible substrate,” IEEE Trans. Antennas Propag., vol. 63, no. 12, pp. 5864-5867, 2015.
H. R. Khaleel, H. M. Al-Rizzo, and D. G. Rucker, “Compact polyimide-based antennas for flexible displays,” IEEE/OSA J. Disp. Technol., vol. 8, no. 2, pp. 91-96, 2012.
A. I. Hammodi, H. Al-Rizzo, A. A. Issac, A. S. Kashkool, K. Gamer, and H. Khaleel, “Studying the effect of bending of the performance of flexible dual band microstrip monopole antenna,” IEEE Conference on Antenna Measurements and Applications (CAMA), Syracuse, NY, pp. 1-3, 2016.