Fast-Switching Microwave Phase Shifter of Coplanar Waveguide Using Ferroelectric Liquid Crystal

Abstract For the first time carbohydrate derivatives were studied as dopants for calamitic smectic phases. Fast switching ferroelectric cells could be realized, and electroclinic effects were observed. By inversion of configuration at a chiral center of these compounds switching times, solubility, and helical twisting power vary by orders of magnitude. The studied derivatives showed modest solubility properties.

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Influence of liquid crystal alignment material and technology on phase modulation of liquid crystal microwave phase shifter

9th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Subdiffraction-limited Plasmonic Lithography and Innovative Manufacturing Technology ◽

10.1117/12.2507330 ◽

2019 ◽

Author(s):

Yingru Hu ◽

Xuhui Peng ◽

Bo Wu ◽

Peng Li ◽

Jiajin Liu

Keyword(s):

Liquid Crystal ◽

Phase Modulation ◽

Phase Shifter ◽

Liquid Crystal Alignment ◽

Microwave Phase Shifter ◽

Crystal Alignment

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P‐206: Late‐News Poster: A Grating‐Aligned Ferroelectric Liquid Crystal Electro‐Optic Shutter for Fast‐Switching and Shock‐Resistant Applications

SID Symposium Digest of Technical Papers ◽

10.1002/sdtp.13308 ◽

2019 ◽

Vol 50 (1) ◽

pp. 1806-1809

Author(s):

Peter J. M. Wyatt ◽

James Bailey ◽

Mamatha Nagaraj ◽

J. Cliff Jones

Keyword(s):

Liquid Crystal ◽

Ferroelectric Liquid Crystal ◽

Fast Switching ◽

Electro Optic ◽

Late News

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Liquid Crystal-Based Enclosed Coplanar Waveguide Phase Shifter for 54–66 GHz Applications

Crystals ◽

10.3390/cryst9120650 ◽

2019 ◽

Vol 9 (12) ◽

pp. 650 ◽

Cited By ~ 15

Author(s):

Jinfeng Li ◽

Daping Chu

Keyword(s):

Liquid Crystal ◽

Phase Shifter ◽

Coplanar Waveguide ◽

Time Domain Reflectometry ◽

Device Fabrication ◽

Metallic Surface ◽

Volume Distribution ◽

60 Ghz ◽

Phase Tuning ◽

Tunable Dielectrics

A 0–10 V bias voltage-driven liquid crystal (LC) based 0°–180° continuously variable phase shifter was designed, fabricated, and measured with insertion loss less than −4 dB across the spectrum from 54 GHz to 66 GHz. The phase shifter was structured in an enclosed coplanar waveguide (ECPW) with LC as tunable dielectrics encapsulated by a unified ground plate in the design, which significantly reduced the instability due to floating effects and losses due to stray modes. By competing for spatial volume distribution of the millimeter-wave signal occupying lossy tunable dielectrics versus low-loss but non-tunable dielectrics, the ECPW’s geometry and materials are optimized to minimize the total of dielectric volumetric loss and metallic surface loss for a fixed phase-tuning range. The optimized LC-based ECPW was impedance matched with 1.85 mm connectors by the time domain reflectometry (TDR) method. Device fabrication featured the use of rolled annealed copper foil of lowest surface roughness with nickel-free gold-plating of optimal thickness. Measured from 54 GHz to 66 GHz, the phase shifter prototype presented a tangible improvement in phase shift effectiveness and signal-to-noise ratio, while exhibiting lower insertion and return losses, more ease of control, and high linearity as well as lower-cost fabrication as compared with up-to-date documentations targeting 60 GHz applications.

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