Dielectric characterization of materials at microwave frequency range

J De Los Santos,J.A Eiras,D Garcia

doi:10.1590/s1516-14392003000100017

J De Los Santos, J.A Eiras + Show 1 more

Open Access

https://doi.org/10.1590/s1516-14392003000100017

Copy DOI

Journal: Materials Research	Publication Date: Jan 1, 2003
Citations: 35	License type: cc-by

Affiliation: Universidade Federal de São Carlos

Abstract

In this study a coaxial line was used to connect a microwave-frequency Network Analyzer and a base moving sample holder for dielectric characterization of ferroelectric materials in the microwave range. The main innovation of the technique is the introduction of a special sample holder that eliminates the air gap effect by pressing sample using a fine pressure system control. The device was preliminary tested with alumina (Al2O3) ceramics and validated up to 2 GHz. Dielectric measurements of lanthanum and manganese modified lead titanate (PLTM) ceramics were carried out in order to evaluate the technique for a high permittivity material in the microwave range. Results showed that such method is very useful for materials with high dielectric permittivities, which is generally a limiting factor of other techniques in the frequency range from 50 MHz to 2 GHz.

Highlights

Requirement of high-speed data transmission has led to a rising interest in the gigahertz region and has prompted research for dielectric resonators at microwave frequencies[1]
The use of ferroelectric materials in phase shifters has increased the investigation of these materials in the microwave range[2] because its excellent ferroelectric and piezoelectric properties
Physical and dielectric properties such as relaxational and motional resonant mechanism can be investigated by analyzing the complex dielectric permittivity in a broad spectral frequency range

Summary

Introduction

Requirement of high-speed data transmission has led to a rising interest in the gigahertz region and has prompted research for dielectric resonators at microwave frequencies[1]. This is true in the case of phase shifters used to electronically command steerable phase array antennas, and where large phase variations for producing radar scans are necessary. Physical and dielectric properties such as relaxational and motional resonant mechanism can be investigated by analyzing the complex dielectric permittivity in a broad spectral frequency range (dielectric dispersion). The nature of the high frequency dielectric dispersion of ferroelectric ceramics in the range of 106 - 109 Hz has been studied since 19403,4.

Objectives

Results

Conclusion