Non-Iterative and Stable Permittivity Extraction of Solid Dielectrics Using a New Formalism Based on Frequency-Domain and Time-Domain Analyses

Hamdullah Öztürk

A non-iterative and stable reference-plane-invariant microwave non-resonant method is proposed for accurate and stable relative permittivity ε r extraction of solid samples without the need for information of sample thickness L . The method first evaluates reference plane transformation distances L 01 and L 02 and then calculates L using the location of first peaks (but not their values) of the magnitudes of forward and backward reflection scattering (S-) parameters in the time-domain. After, this information is utilized for non-iterative and stable determination of ε r in frequency-domain. Ac ...Daha fazlası

Simple and inexpensive microwave setup for industrial based applications: Quantification of flower honey adulteration as a case study

A simple and inexpensive microwave measurement setup based on measurements of magnitudes of transmission properties (| S 21|dB ) is proposed for industrial-based microwave aquametry (moisture or water content) applications. An easy-to-apply calibration procedure based on normalization is implemented to eliminate systematic errors in the measurement system. As a case study, we applied this setup for the quantification of water-adulteration in flower honey. After validating this system by distilled water and pure flower honey measurements, |S 21|dB measurements of the pure flower honey with vari ...Daha fazlası

De-embedding technique relying on a new formalism for two-port network characterization using raw S-parameter measurements

A de-embedding technique based on a new formalism is proposed for determining all scattering (S-) parameters of a two-port network (or sensing area) using raw (uncalibrated) measurements at microwave frequencies. It uses raw S-parameter measurements of a reflecting line, (direct and reversed configurations) a non-reflecting line, and (direct and reversed configurations) a device (e.g., only three different topologies). In addition to its unique advantage that it fully and uniquely determines S-parameters of a two-port network, it also has the capability of determining terms of error networks, ...Daha fazlası

Dielectric Constant Measurement Using Time-Domain Shifted Metal-Backing Measurements

— A free-space microwave method is proposed for accurate dielectric constant εr measurement of flat dielectric samples using time-domain measurements. It does not require any reference data (calibration-independent) and thickness information for εr measurement. Besides, it uses only two power peaks of reflected signals of one sample with offset metal termination. It is first validated by simulations and numerical analysis. Free-space εr measurements of three low-loss dielectric samples [polypropylene (PP), polyethylene (PE), and polyoxymethylene (POM)] are then performed for validation of our ...Daha fazlası

Detection and quantification of alkali-silica-reaction (ASR) gel in cement-based mortars using microwave spectral and temporal transmission properties

Microwave transmission measurements in time-domain, as a new measurement tool, were carried out to detect and quantify alkali-silica-reaction (ASR) within mortar specimens. To examine the potential of time-domain transmission measurements for ASR detection and its any possible quantification, transmission measurements in frequency-domain and time-domain of two different sets (reactive and non-reactive) of mortar specimens were performed approximately every 2 or 3 days over 29 days after demolding the specimens, by a rectangular waveguide operated at 2.60–3.95 GHz. Thickness expansion measureme ...Daha fazlası

Parameter extraction method for reflection-asymmetric bianisotropic metamaterial slabs using one-port measurements

An effective microwave method is developed for extracting electromagnetic properties of bianisotropic metamaterial (MM) slabs. As a non-iterative method, it utilizes only the one-port (air-backed and metalbacked MM slab) scattering (S-) parameter measurements. This is a useful feature especially for vector network analyzers, such as MS46131A, MS46121B, and R60, performing only one-port S-parameter measurements. Electromagnetic properties of a bianisotropic MM slab formed by C-shaped resonators are measured by an Xband (8.2–12.4 GHz) rectangular waveguide setup. The effect of any gap between th ...Daha fazlası

Application of the Kalman Filter/Smoother for accurate material characterization of planar dielectric samples by using free-space measurements at sub-THz frequencies

The Kalman Filter/Smoother, as a new post-calibration technique, has been successfully applied for accurate relative complex permittivity 𝜀𝑟 extraction of planar dielectric samples using sub-THz free-space transmission scattering parameter 𝑆21 measurements. Extracted 𝜀𝑟 of the planar polyvinylchloride and polymethylmethacrylate samples without any post-calibration procedure produced non-physical results (violation of the passivity principle) over some frequencies in three frequency bands between 50 and 75 GHz, 75 and 110 GHz, and 110 and 170 GHz, indicating the importance of the application of ...Daha fazlası

Permittivity extraction of soil samples using coaxial-line measurements by a simple calibration

Hamdullah Öztürk

A new microwave method is proposed for accurate determination of complex permittivity εrs = ε rs − − jε rs of soil samples inserted over a holder within the Electronic Industries Association (EIA) 1-5/8” coaxial measurement cell. Such a determination could be indirectly correlated with the volumetric moisture content of soil samples by microwave measurements. The method has three main advantages. First, it utilizes a simple calibration procedure involving uncalibrated measurements of an empty cell, the same cell loaded with a soil holder (a dielectric sample), and the same cell with a soil sam ...Daha fazlası

Energy Harvesting based Wireless Sensor Networks Protocols

On the Throughput of Pure ALOHA with Different Power Levels for Wireless Sensor Networks

Real-time Observation of Earthquake Disaster Zones with Wireless Sensor Networks-based Solutions

General line-line method for propagation constant measurement of non-reciprocal networks

A general ‘‘line-line’’ (LL) method is proposed for propagation constant determination (𝛾 + and 𝛾 −) of nonreciprocal networks using multiple reference networks. The new formalism provides flexibility in implementation of LL methods so that not only more accurate 𝛾 + (and 𝛾 −) could be retrieved but also the effect of inaccurate length information of the non-reciprocal network on 𝛾 + (and 𝛾 −) evaluation could be suppressed. For validation of the method, 𝛾 + and 𝛾 − of a microwave phase shifter (a nonreciprocal network) are determined using uncalibrated scattering parameter measurements at X-b ...Daha fazlası