Liquid Metal-Enabled Multi-Functional Passive Device

This paper proposes a liquid metal (LM)-enabled multi-functional passive device that can switch between a filter and a phase shifter. It consists of a half-mode substrate integrated waveguide (HMSIW), grounded coplanar waveguide (GCPW)-to-HMSIW transition, five rectangle slots, and two rows of via-pad-slot (VPS) structures. The rectangle slots are etched to the center of the HMSIW, while the VPS structures are placed in the HMSIW in parallel to the side wall. When the VPS structures are completely covered by the LM, the device operates as a 5-pole filter. When the rectangle slots are covered instead by the LM and the VPS structures are covered by the LM one by one, the device operates as a tunable phase shifter. Hence, it can switch its functions between a filter and a phase shifter. There is the scope to integrate more functions, such as slot antennas and switches.