3D Printed Compact Dual-Band Bandpass Filter Based on Modified Strong Coupled Coaxial Resonator

Abstract

This work proposes and analyzes a modified strongly coupled coaxial resonator (M-SCCR) for the first time. Unlike the conventional SCCR that is typically used to design single-band filter, the M-SCCR can be applied on design dual-band filters. This can be achieved due to the introduced stepped coupled metal plate allows for the flexible adjustment of strongly coupled frequencies (SCM) and coaxial mode (CM) frequencies. The inductive window and extra cylinder posts are incorporated to obtain control of inner coupling and external coupling independently. For demonstration, a four-pole dual-band controllable filter is designed, simulated, and manufactured. Commercial 3-D metal printing and laser cutting techniques are adopted to manufacture the filter enclosure and inside metal plates. The measured results agreed well with the simulated ones.