The flexible bandpass filter on polyimide substrate for wireless communications systems

A coplanar waveguide flexible filter based on the polyimide substrate was fabricated by self-metallization technology. The measured results indicate that the central frequency of the proposed filter is 2.5 GHz, the minimum insertion loss is −0.71 dB and the return loss is better than −20 dB. To test the conformal characteristics of the filter, bending and folding tests were performed. The test results show that the measured and simulated results are basically the same when the filter is bent and folded. The flexible filter fabricated by self-metallization technology is expected to be one of the components of future flexible wireless communication systems.