A Fully Additively Manufactured Reconfigurable Millimeter-Wave Bandpass Filter Based on VO₂ Dielectric Layer

In this paper, a fully additively manufactured reconfigurable millimeter-wave bandpass filter is presented. This filter is based on a printed VO₂ layer and TPC substrate. An additively manufactured heating circuit is integrated on the back of the filter, which is engineered to heat the printed VO₂ layer. By utilizing VO₂ inks with varying concentrations, the filter can have different tuning range. To validate our design and manufacturing concept, a filter based on a 10% VO₂ ink was fabricated and tested. The resulting filter demonstrates a reconfigurable center frequency with consistent fractional bandwidth, shifting from 26.1 GHz to 24.9 GHz, resulting in a 4.71% frequency tuning range.