Fully Inkjet-Printed Three-Dimensional Bandpass Filter on Liquid Crystal Polymer Substrate

Abstract

This paper has presented a three-dimensional bandpass filter using fully inkjet-printing technology, which can reduce chip size and improve performance. Inkjet-printed silver film and SU-8 polymer film were used as metal layer and dielectric layer to achieve three-dimensional structure. Vertical interconnections were realized using inkjet-printing technology filled by silver ink and isolated by SU-8 film. Fully inkjet-printed hairpin bandpass filter with two meandered half-wavelength microstrip lines was fabricated for cross-coupled and size reduction. The minimal insertion loss and maximal return loss at 12 GHz were -2.35 dB and -17.4 dB, respectively. Fully inkjet-printed three-dimensional bandpass filter demonstrated compact size and acceptable performance which make it attractive for RF applications.