Fully Flexible, Polymer based Microwave Devices Part II: Flexible Antennas and Performance Evaluation

In this work, we have investigated polymer-based flexible antennas from commercial and modified polymers, which are competitive to rigid PCB technology. Classical designs of the patch and bow-tie antennas have been realized and showed that the realized gain can get up to 9.16dBi for the patch and 7.9dBi for the bow-tie antennas. The effects of the dielectric loss and conductivity on the antennas’ performance in S-band have been analyzed in order to find limits for further material engineering and the optimum trade-off between microwave and mechanical performance. The bending effects have been investigated, and it has been found that E-plane bend inside can boost the antenna gain from 8.6dBi to 10.1dBi with the frequency shift from 2.5 GHz to 2.4 GHz for the patch and 7.9dBi to 11.3dBi at 3.1 GHz for the bow-tie antennas. The non-classical π-shaped conductors’ edges lead to additional fringing fields, which have an effect on the antenna’s gain and can be explored and exploited for further performance improvements. The new recipes for low-loss, low-Dk dielectric materials, and chemical integration between conducting