A resonant-cavity method for measuring dielectric properties at ultrahigh frequencies

1944 ◽  
Vol 63 (12) ◽  
pp. 1092-1098 ◽  
Author(s):  
C. N. Works ◽  
T. W. Dakin ◽  
F. W. Boggs
Keyword(s):  
Dielectric Properties ◽  
Resonant Cavity ◽  
Cavity Method ◽  
Ultrahigh Frequencies

High Performance Porous Wave-Transmitting Silicon Nitride Ceramics by Gel-Casting Technique

2012 ◽  
Vol 512-515 ◽  
pp. 869-872 ◽  
Author(s):  
Jian Zhang ◽  
Ji Wei Chen ◽  
Hong Jie Wang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Flexural Strength ◽  
High Performance ◽  
Sintering Temperature ◽  
Resonant Cavity ◽  
Porous Ceramics ◽  
Cavity Method ◽  
Pore Former ◽  
Gel Casting

Porous wave transmitting Si3N4 ceramics have been of great interest and technological importance in aerospace area. In this paper, the high performance wave transmitting porous Si3N4 ceramics was prepared by gel-casting method, without any pore-former. The porosity was controlled by the solid content of the slurry and the sintering temperature. The flexural strength and dielectric properties of the material were determined by three bending method and a resonant cavity method. The relationship of the dielectric constant versus the sintering temperature was discussed, and the effect of porosity on dielectric properties was investigated also. As a result, the flexural strength of the porous Si3N4 is 40-200MPa with porosity of 67-45%, dielectric constant of 2.2-3.4 in the frequency of 8GHz at room temperature. With the increase of porosity, both the dielectric constant and dielectric loss decreased. This technique is considered to be a potentially useful method to fabricate the porous ceramics with complex shape.

Modeling The Microwave Frequency Dielectric Properties of Thermoplastic Composite Materials

1992 ◽  
Vol 269 ◽  
Author(s):  
Mitchell L. Jackson ◽  
Curtis H. Stern
Keyword(s):  
Composite Materials ◽  
Dielectric Properties ◽  
Volume Fraction ◽  
Perturbation Technique ◽  
Resonant Cavity ◽  
Microwave Frequency ◽  
Thermoplastic Composite ◽  
Fiber Volume ◽  
Thermoplastic Matrix ◽  
Rotation Procedure

ABSTRACTMixture models were studied in an effort to predict the microwave frequency permittivities of unidirectional-fiber-reinforced thermoplastic-matrix composite materials as a function of fiber volume fraction, fiber orientation relative to the electric field, and temperature. The permittivities of the constituent fiber and plastic materials were measured using a resonant cavity perturbation technique at 9.4 GHz and at 2.45 GHz. The permittivities of the composite specimens were measured using a reflection cavity technique at 9.4 GHz and at 2.45 GHz. Simple “rule-of-mixtures” models that use the fiber and plastic permittivities have been found to approximate the complex dielectric properties of the composite for varied fiber volume fractions. The permittivities of oriented composites were modeled using a tensor rotation procedure. Composite permittivities were modeled with temperature up to the glass transition temperature of the thermoplastic matrix.

Numerical enhancements of the microwave resonant cavity method for plasma diagnostics

2019 ◽  
Vol 28 (10) ◽  
pp. 105007 ◽  
Author(s):  
J Faltýnek ◽  
V Kudrle ◽  
J Tesař ◽  
M Volfová ◽  
A Tálský
Keyword(s):  
Plasma Diagnostics ◽  
Resonant Cavity ◽  
Cavity Method ◽  
Microwave Resonant Cavity
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