Miniaturized Liquid Crystal Slow Wave Phase Shifter Based on Nanowire Filled Membranes

• Published in: IEEE microwave and wireless components letters Vol. 28; no. 8; pp. 681 - 683
• Main Authors: Jost, Matthias, Gautam, Jay S. K., Gomes, Leonardo G., Reese, Roland, Polat, Ersin, Nickel, Matthias, Pinheiro, Julio M., Serrano, Ariana L. C., Maune, Holger, Rehder, Gustavo P., Ferrari, Philippe, Jakoby, Rolf
• Format: Journal Article
• Language: English
• Published: IEEE 01.08.2018; Institute of Electrical and Electronics Engineers
• Subjects: Copper; Dielectrics; Electric power; Engineering Sciences; Glass; liquid crystal (LC); Microstrip; millimeter-wave; Phase measurement; phase shifter; Phase shifters; slow wave; Transmission line measurements; 5G; slow wave; liquid crystal (LC); millimeter-wave; phase shifter
• ISSN: 1531-1309; 1558-1764
• DOI: 10.1109/LMWC.2018.2845938

This letter presents the realization of a miniaturized liquid crystal slow wave phase shifter at <inline-formula> <tex-math notation="LaTeX">V </tex-math></inline-formula>-band. It is based on a microstrip topology, where the ground plane is realized by a porous alumina membrane filled with metallic nanowires, all of them being connected with each other by a metallic ground plane at the membrane's back. While the magnetic field can pass the nanowires almost unperturbed, the electric field is confined in between the signal electrode and the tips of the nanowires. After deembedding, the meander line phase shifter shows a matching always better than −10 dB, while exhibiting an insertion loss between 1.5 and 2.5 dB from 40 to 67 GHz. This results in a figure-of-merit for passive phase shifters of 33 dB to 45°/dB, accompanied with a phase shift of 55°-100°.