Adjustable resonant cavity for measuring the complex permittivity of dielectric materials
نویسندگان
چکیده
An adjustable resonance cavity was developed to measure the complex permittivity of dielectric materials. The cavity has an inner diameter of 16.400 cm and an inner height of 2.54 cm. The aluminum stationary wall holder was positioned about 10.8 cm above the top of the cavity. It was fixed into place by three 1.27-cm-diam linear shafts. By suspending from the wall holder, the movable wall moved vertically by sliding on 1.27 cm bore-closed ball bushings. By turning a 1 in.-12 nut, the movable wall could be positioned so that the cavity height equaled the height of the sample. Therefore, this enables the measurement of the permittivity of samples with heights between 0.88 and 1.91 cm and radius between 1.27 and 3.18 cm. The complex permittivity of the sample was calculated based upon the sample dimensions, central frequency of TMono modes, and Q factor of the resonance curve using an exact solution. The complex permittivity was measured at the three lowest modes, where the frequency span is 1–4 GHz. © 2000 American Institute of Physics. @S0034-6748~00!01108-4#
منابع مشابه
Frequency domain complex permittivity measurements at microwave frequencies
Overview of frequency domain measurement techniques of the complex permittivity at microwave frequencies is presented. The methods are divided into two categories: resonant and non-resonant ones. In the first category several methods are discussed such as cavity resonator techniques, dielectric resonator techniques, open resonator techniques and resonators for non-destructive testing. The gener...
متن کاملPermittivity Measurements with a Resonant Cavity to Develop Human Tissue Phantoms for Microwave Imaging
In order to create human tissue phantoms for a microwave imaging system, a method to determine the complex permittivity is needed. For this reason a cavity perturbation method has been analyzed and used to perform measurements characterizing the complex permittivity of different fluid mixtures. Results show good agreement on single frequency between the measurement with the reentrant cavity and...
متن کاملStructural and Microwave Dielectric Properties Of
Strontium sodium niobate ceramics are prepared by solid state reaction method. The crystal structures of these ceramics are studied by X-ray powder diffraction method. These materials are found to crystallize in the tetragonal tungsten bronze type structure and the unit cell parameters are calculated. The microstructural features were studied using scanning electron microscope. The real and ima...
متن کاملComplex Permittivity Determination from Propagation Constant Measurements
This letter presents a new transmission line method for measuring the complex permittivity of dielectric materials using propagation constant measurements. In contrast to previous methods, a network analyzer calibration is unnecessary since calibrated scattering parameters are not required. We use measurements in X-band waveguide to show that this technique compares well with the transmission/r...
متن کاملComplex permittivity measurements using cavity perturbation technique with substrate integrated waveguide cavities.
Cavity perturbation technique is widely used in the measurements of complex dielectric permittivity of materials due to its accuracy and ease of configuration. This paper presents the theoretical formulas for the evaluation of complex permittivity of materials using cavity perturbation technique with substrate integrated cavity resonators. With the proposed formulas, the use of various planar c...
متن کامل