Rethinking liquid crystal tunable phase shifter design with inverted microstrip lines at 1–67 GHz by dissipative loss analysis
File(s)
Published version
Author(s)
Li, Jinfeng
Type
Journal Article
Abstract
Growing 5G/6G phased-array beam-steering applications, for which liquid crystal (LC) is one of the enabling technology candidates, have sparked interest in the modulation of the phase (and amplitude) of microwave and millimeter-wave signals. In this communication, fresh insights into the systematic design analysis of a 1–67 GHz passive inverted microstrip line (IMSL) phase shifter filled with highly anisotropic LC as tunable dielectric media are obtained. Based on waveguide disturbance tests to characterize the dielectric properties of the non-tunable PCB and tunable LC used in the IMSL phase shift device filled with a GT3-24002 LC layer (125 µm thick) partially enclosing a 220 µm wide, 17 µm thick, 1.35 cm long copper core line, a 0–π differential phase shift in the 1–67 GHz range with less than 2 dB insertion loss is reported. Dissipative loss analysis shows that the dielectric absorption of the LC is 21.28% of the input signal power at 60 GHz. Further investigation is performed to quantify the impacts of dielectric substrate thicknesses (PCB and LC) on the wave-occupied volume ratio (and hence the phase tuning range), as well as on dissipative losses (including conductor loss and dielectric loss). Specifically, conductor loss is observed to follow a linear relationship with the reciprocal of the LC thickness.
Date Issued
2023-01-13
Date Acceptance
2023-01-12
Citation
Electronics (Basel), 2023, 12 (2), pp.1-18
ISSN
2079-9292
Publisher
MDPI AG
Start Page
1
End Page
18
Journal / Book Title
Electronics (Basel)
Volume
12
Issue
2
Copyright Statement
© 2023 by the author. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://www.mdpi.com/2079-9292/12/2/421
Publication Status
Published
Article Number
421
Date Publish Online
2023-01-13