AMC-Based Miniaturized Waveguide With Reconfigurable Pass-Bands Below Cut-Off Frequency and Quasi-TEM Mode

Abstract

This work introduces an innovative miniaturized transverse electromagnetic (TEM) waveguide design, which is 60% smaller than conventional metal waveguides. The proposed waveguide offers two distinct electronically reconfigurable passbands well below the cutoff frequency. This has been achieved by using sidewalls composed of reconfigurable artificial magnetic conductors (AMC), optimized to operate at 3.51 GHz and 4.37 GHz. By replacing the metal sidewalls with an AMC structure, a TEM mode can be sustained within the confined space enclosed by the waveguide structure, which otherwise would not exist in a conventional metal waveguide. This eliminates typical cut-off frequency constraints that limit the size of conventional waveguides, thereby enabling a significant miniaturization of the waveguide design. The work also proposes a reconfigurable AMC design whose operating frequency can be dynamically adjusted by applying or removing a direct current (DC) bias across the integrated PIN diodes. Additionally, this work utilizes 3D printing technology to fabricate a functional waveguide, highlighting the design’s compactness, cost-effectiveness, versatility, and fast prototyping capabilities for a wide range of microwave applications. This study therefore demonstrates the potential of using reconfigurable AMCs for compact and versatile waveguide designs that can be 3D-printed for various practical use cases and modern microwave applications.