Design, Simulation, Fabrication and Testing of Flexible Bow-Tie Antennas

Design, simulation, fabrication and measurement of two different novel flexible bow-tie antennas, a conventional and a modified bow-tie antenna with reduced metallization, are reported in this paper. The antennas are mounted on a flexible substrate fabricated at the Flexible Display Center (FDC) of Arizona State University (ASU). The substrate is heat stabilized polyethylene naphthalate (PEN) which allows the antennas to be flexible. The antennas are fed by a microstrip-to-coplanar feed network balun. The reduction of the metallization is based on the observation that the majority of the current density is confined towards the edges of the regular bow-tie antenna. Hence, the centers of the triangular parts of the conventional bow-tie antenna are removed without compromising significantly its performance. The return losses and radiation patterns of the antennas are simulated with HFSS and the results are compared with measurements, for bow-tie elements mounted on flat and curved surfaces. The comparisons show that there is an excellent agreement between the simulations and measurements for both cases. Furthermore, the radiation performance of the modified bow-tie antenna is verified, by simulations and measurements, to be very close to the conventional bow-tie.