"

Cookies ussage consent

Our site saves small pieces of text information (cookies) on your device in order to deliver better content and for statistical purposes. You can disable the usage of cookies by changing the settings of your browser. By browsing our site without changing the browser settings you grant us permission to store that information on your device.

I agree, do not show this message again.

Frequency resonant behaviour of the effective permittivity for a polyvalent liquid crystal in microwave range

D. IONESCU1,* , I. B. CIOBANU2,* , I. RADINSCHI2

Affiliation

  1. "Gh. Asachi" Technical University, Faculty of Electronics and Telecommunications, Bd. Carol, 1,700506, Iasi, Romania
  2. "Gh. Asachi" Technical University, Department of Physics, Bd. D. Mangeron, 59 A, 700050, Iasi, Romania

Abstract

We consider a thermotropic polyvalent liquid crystal, which presents different local orders for different temperature ranges. The aim of our paper is to perform a material study, illustrating its specific characteristics. We determine the effective permittivity of the material, in the microwave frequency range, where the practical results are difficult to obtain. We follow these steps: structure simulations using a high level program, measurements for punctual frequencies in the microwave range, and theoretical calculation based on the Rayleigh bi-dimensional model. The effective permittivity curves plotted against frequency are obtained. The curves illustrate the frequency dependence of the determined quantity, which is not predicted by the existing theories, and indicate the resonances, which are of great interest in practice as they represent breakups of electrical properties of the material..

Keywords

Polyvalent liquid crystal, Relative effective permittivity, Optical anisotropy, Electrical resonances, Microwave range.

Submitted at: April 2, 2007
Accepted at: Aug. 18, 2007

Citation

D. IONESCU, I. B. CIOBANU, I. RADINSCHI, Frequency resonant behaviour of the effective permittivity for a polyvalent liquid crystal in microwave range, Journal of Optoelectronics and Advanced Materials Vol. 9, Iss. 8, pp. 2608-2616 (2007)