Rapid High Temperature Measurement of Microwave Dielectric Properties

1992 ◽  
Vol 269 ◽  
Author(s):  
W.R. Tinga
Keyword(s):  
High Temperature ◽  
Power Level ◽  
Measurement Techniques ◽  
Microwave Dielectric Properties ◽  
Dielectric Measurement ◽  
Small Samples ◽  
Complex Dielectric Constant ◽  
Dual Frequency ◽  
Microwave Source ◽  
Microwave Dielectric

ABSTRACTPractical high temperature (above 500°C) dielectric measurement techniques are reviewed stating both advantages and limitations of known methods. Details of a new and practical dual frequency microwave high temperature dielectrometer are discussed. This dielectrometer technique is capable of measurements beyond 2000°C. Both heating of the small samples and the measurement of their complex dielectric constant is done simultaneously using both a medium power (60W) microwave source and a low power scalar network analyzer. Good accuracy is obtained and the measurement is capable of being totally automated. Presently, a measurement and heating cycle time of about 20 s is needed to completely characterize the sample's microwave dielectric response from 300°C to 1600°C. A second high temperature dielectrometer technique is discussed which requires only one microwave source of medium power level (60W). This method requires only the reflected power to be monitored during the microwave heating of the sample to obtain the complex permittivity versus temperature curve.

High-Temperature Microwave Dielectric Properties and Processing of JSC-1AC Lunar Simulant

2013 ◽  
Vol 26 (4) ◽  
pp. 874-881 ◽  
Author(s):  
Shawn M. Allan ◽  
Brandon J. Merritt ◽  
Brittany F. Griffin ◽  
Paul E. Hintze ◽  
Holly S. Shulman
Keyword(s):  
High Temperature ◽  
Dielectric Properties ◽  
Microwave Dielectric Properties ◽  
Microwave Dielectric ◽  
Lunar Simulant

Structure and microwave dielectric properties of (Zn1−xNix)TiO3 ceramics

2003 ◽  
Vol 18 (5) ◽  
pp. 1067-1072 ◽  
Author(s):  
Hyo Tae Kim ◽  
Joon-Cheol Hwang ◽  
Joong-Hee Nam ◽  
Byung Hyun Choi ◽  
Michael T. Lanagan
Keyword(s):  
Dielectric Constant ◽  
Phase Composition ◽  
Dielectric Properties ◽  
Phase Distribution ◽  
Spinel Phase ◽  
Measurement Techniques ◽  
Microwave Dielectric Properties ◽  
Rutile Phase ◽  
Microwave Measurement ◽  
Microwave Dielectric

Dielectric ceramics in the system (Zn1−xNix)TiO3, x = 0 to 1 were synthesized by the solid-state reaction route. The phase distribution, microstructure, and dielectric properties were characterized using powder x-ray diffraction analysis, electron microscopy, and microwave measurement techniques. Three phase composition regions were identified in the specimens sintered at 1150 °C: [spinel + rutile] at 0 ≤ x ≤ 0.5, [spinel + ilmenite + rutile] at 0.5 < x ≤ 0.8, and [ilmenite] phase at 0.8 < x ≤ 1. For the 0 ≤ x ≤ 0.5 region, the amount of Ti-rich precipitates incorporated into the spinel phase decreased with the Ni content at 0 ≤ x ≤ 0.5, with a concomitant increase of the rutile phase. The microwave dielectric properties depended on the phase composition and volume according to the three typical phase regions, where the relative amount of rutile to the spinel or ilmenite determined the dielectric properties. The dielectric constant as a function of Ni addition was modeled with a Maxwell mixing rule. An optimum phase distribution was determined in this system with dielectric constant of 22, a Q × f of 60,000, and a low temperature coefficient of the resonant frequency.

High Temperature Dielectric Measurements on Ceramics

1992 ◽  
Vol 269 ◽  
Author(s):  
M Aral ◽  
J G P Binner ◽  
G E Carr ◽  
T E Cross
Keyword(s):  
High Temperature ◽  
Dielectric Properties ◽  
Alternative Energy ◽  
Elevated Temperatures ◽  
Microwave Dielectric Properties ◽  
Microwave Frequency ◽  
Dielectric Measurements ◽  
Microwave Dielectric ◽  
The University ◽  
Processing Group

ABSTRACTThe use of microwave frequency radiation as an alternative energy source for processing materials is currently receiving considerable worldwide attention. The ability of a material to extract energy from the microwave field depends upon its dielectric properties, however these change as the material heats. There is, therefore, a need for obtaining measurements of the microwave dielectric properties at elevated temperatures. This paper outlines some of the current work on high temperature dielectric measurements which is in progress at the University of Nottingham as part of the Materials and Microwave Processing Group initiative and some results on engineering ceramics are presented.

Shifting τf Value of (Mg0.95Co0.05)TiO3 Ceramics by Ca0.61Nd0.78/3TiO3 Addition

2013 ◽  
Vol 807-809 ◽  
pp. 2703-2706
Author(s):  
Ping Cheng Chen ◽  
Chung Long Pan ◽  
Wei Cheng Lin ◽  
Chun Hsu Shen
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Resonant Frequency ◽  
Temperature Coefficient ◽  
Significant Role ◽  
Microwave Dielectric Properties ◽  
Dielectric Measurement ◽  
Zero Temperature ◽  
Microwave Dielectric

Modification of (Mg0.95Co0.05)TiO3ceramics by Ca0.61Nd0.78/3TiO3addition was investigated. The Ca0.61Nd0.78/3TiO3content plays a significant role in improving the dielectric properties. Microwave dielectric measurement showed an increase in dielectric constant (εr) and temperature coefficient of the resonant frequency (τf) and a decrease inQvalue with increasing Ca0.61Nd0.78/3TiO3content. By properly adjusting the Ca0.61Nd0.78/3TiO3content, zero temperature coefficient of resonate frequencyτfcan also be obtained. It becomes more promising in the application of wireless system.At 1375°C, the 0.85(Mg0.95Co0.05)TiO3-0.15Ca0.61Nd0.78/3TiO3ceramics possesses excellent microwave dielectric properties: a dielectric constant εr of 24.37, aQfvalue of 66200 ( at 7 GHz ) and a τf value of-1.4 ppm/°C.

scholarly journals Complex dielectric modulus and relaxation response at low microwave frequency region of dielectric ceramic Ba6-3xNd8+2xTi18O54

2014 ◽  
Vol 04 (04) ◽  
pp. 1450034 ◽  
Author(s):  
Chian Heng Lee ◽  
Jumiah Hassan ◽  
Mansor Hashim ◽  
Raba'ah Syahidah Aziz ◽  
Norlaily Mohd Saiden
Keyword(s):  
Dielectric Properties ◽  
High Dielectric Constant ◽  
Microwave Dielectric Properties ◽  
Microwave Frequency ◽  
Dielectric Measurement ◽  
Low Loss ◽  
Dielectric Ceramic ◽  
Microwave Dielectric ◽  
Dielectric Modulus ◽  
High Dielectric

The desirable characteristics of Ba 6-3x Nd 8+2x Ti 18 O 54 include high dielectric constant, low loss tangent, and high quality factor developed a new field for electronic applications. The microwave dielectric properties of Ba 6-3x Nd 8+2x Ti 18 O 54, with x = 0.15 ceramics at different sintering temperatures (600–1300°C) were investigated. The phenomenon of polarization produced by the applied electric field was studied. The dielectric properties with respect to frequency from 1 MHz to 1.5 GHz were measured using Impedance Analyzer, and the results were compared and analyzed. The highest dielectric permittivity and lowest loss factor were defined among the samples. The complex dielectric modulus was evaluated from the measured parameters of dielectric measurement in the same frequency range, and used to differentiate the contribution of grain and grain boundary.

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