Principle Demonstration of a Mechanically Tunable UHF Bandpass Filter Based on SIR Coaxial Resonators

This paper describes an original topology of tunable SIR coaxial filter. The proposed solution combines, moving cylinders, and rotating shutters associated with coupling arches. This topology allows the central frequency to sweep on a large frequency range of almost one octave, while controlling the bandwidth. To illustrate the principle, a third order filter was fabricated with an additive manufacturing process. The experimental results are compared with simulated data obtained with HFSS.