Abstract-A promising microwave method has been proposed to accurately determine the complex permittivity of thin materials. The method uses amplitude-only scattering parameter measurements at one frequency for this purpose. It resolves the problems arising from any offset of the sample inside its cell in complex reflection scattering parameter measurements and from any uncertainty in sample thickness in transmission scattering parameter measurements. The method determines unique permittivity since, for thin samples, multi-valued trigonometric terms can be linearized. It uses higher order approximations to extract highly accurate permittivity values. It works very well in limited frequency-band applications or for dispersive materials since it is based upon point-by-point (or frequency-byfrequency) measurements. For validation of the method, we measured the complex permittivity of two thin polytetrafluoro-ethylene (PTFE) samples.

Measurements of Kβ/Kα intensity ratios in elements with 22⩽Z⩽69 have been carried out by stimulating the emission of K characteristic radiation by 59.5 keV monochromatic photons. The x-rays were measured using a Si(Li) detector (160 eV FWHM at 5.9 keV). The experimental results were compared with other theoretical and experimental values.

Calibration-independent microwave methods have successfully been used to determine the complex permittivity, ε, of dielectric materials by eliminating the necessity of the calibration before measurements. However, there are three main problems of these methods. These are: (a) they suffer from thickness uncertainty in the second sample for methods which utilize propagation constant measurements, (b) they require precise or exact shifting distance of the sample within its cell location (a waveguide or coaxial-line section) and (c) they may produce some singularity points in the measured ε. In this paper, we propose a new calibration- independent method which simultaneously eliminates all these drawbacks while extracting the nonsingular complex permittivity of solid materials. We use the uncalibrated scattering parameter measurements of the cell with the dielectric sample located arbitrarily and of extra cells attached to the same cell to achieve this goal. In addition, in the literature, there is a need for a technique which auto-monitors the accurateness of calibration-independent measurements, which are used for the extraction of electrical properties of materials. In this paper, we also propose a simple self-checking technique, which is independent of electrical properties and thickness of materials and the location of materials inside the measurement cell. Therefore, this technique gives information about the performance of measurements before extracting electrical properties of materials. We validate the proposed method by measurements of the ε of polyvinyl-chloride (PVC) and Plexiglas samples at X-band (8.2–12.4 GHz)

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