Microwave characteristics of liquid-crystal tunable capacitors

Author

Yeh, J. Andrew ; Chang, C. Alex ; Cheng, Chih-Cheng ; Huang, Jing-Yi ; Hsu, Shawn S H

Author_Institution

Inst. of Electron. Eng., Nat. Tsing-Hua Univ., Hsinchu, Taiwan

Volume

26

Issue

7

fYear

2005

fDate

7/1/2005 12:00:00 AM

Firstpage

451

Lastpage

453

Abstract

This letter investigates the microwave characteristics of the liquid crystal tunable capacitors for the first time. With the dielectric anisotropy properties, the liquid crystal capacitors present very different characteristics compared to the semiconductor or MEMS tunable capacitors. A quality factor of 310 with a control voltage of 5 V was achieved at 4 GHz. A tuning range of 25.3% for the control voltages from 0 to 5 V was obtained at 5 GHz. The results demonstrate the potential applications of liquid crystals as dielectric materials for capacitors with high quality factors and wide tuning ranges at high frequencies, particularly suitable for the future flexible electronics with transparent substrates.

Keywords

Q-factor; capacitors; dielectric materials; liquid crystal devices; microwave devices; 0 to 5 V; 4 GHz; 5 GHz; MEMS tunable capacitor; dielectric anisotropy properties; dielectric materials; flexible electronics; liquid-crystal tunable capacitors; microwave characteristics; quality factor; semiconductor tunable capacitor; transparent substrates; tuning ranges; Anisotropic magnetoresistance; Capacitors; Dielectric liquids; Dielectric materials; Frequency; Liquid crystals; Micromechanical devices; Q factor; Tuning; Voltage control; Liquid crystal; microwave; tunable capacitors;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2005.851118

Filename

1458953