The equivalent anisotropic material parameters of metal dummy fills in a CMOS chip were extracted through an eigenmode analysis of a unit-cell of a space filled with metal dummies. The validity of the parameters was confirmed by comparing the S-parameters of a parallel-plate waveguide with the metal dummy fills and their effective material properties. The validity of the effective material properties was also confirmed by using them in a simulation of an on-chip dipole antenna.

We propose a new swept-frequency measurement method for the electromagnetic characterization of materials. The material is a multilayer cylinder that pierces a rectangular waveguide through two holes in the narrow waveguide walls. The complex permittivity and permeability of the material are calculated from measured S-parameters as an inverse problem. To this aim, the paper develops a complete electromagnetic formulation of the problem, where the effects of material insertion holes are taken into consideration. The formulation is validated through the measurement of ferrite and water samples in the S-band.

An equivalent network analysis for an arrangement that combines a microstrip line and coaxial conductor for the purpose of measuring permeability is discussed in this paper. The measurement circuit used consists of a coaxial conductor with a sample housed inside and a short microstrip line connected to both sides. The coaxial conductor is composed of an electrically grounded coaxial metal pipe with open ends and a center conductor. Equivalent networks for this arrangement are investigated to determine the complex permeability from the impedance of the measurement circuit. We have employed a π network composed of a resistor and an inductor connected in series, and shunt capacitors as the equivalent circuit for the measurement portion. It has been found that the measurement error ratio of less than a few percent can be obtained for most frequency ranges of 10 MHz to 500 MHz.

In this paper, a new swept-frequency method for the measurement of the complex permittivity and permeability of materials is proposed. The method is based on the S-parameters measurement of a cylindrical material placed inside a rectangular waveguide, where the axis of the cylinder is perpendicular to the narrow waveguide walls. The usage of cylinders in measurement is beneficial because they are easy to fabricate and handle. A novel exact solution of the field scattered by the cylinder is developed. The solution is based on expanding the field in a sum of orthogonal modes in cylindrical coordinates. Excitation coefficients relating the cylindrical scattered field to the waveguide modes are derived, and are used to rigorously formulates the S-parameters. Measurement are performed in the S-band with two dielectric materials (PTFE, nylon), and in the X-band with one magnetic material (ferrite epoxy). The measurement results agree with those from the literature.

The waveguide-penetration method is a method to measure the electrical properties of materials. In this method, a cylindrical object pierces a rectangular waveguide through a pair of holes at the centre of its broad walls. Then, the complex permittivity and permeability of the object are estimated from measured S-parameters after TRL calibration. This paper proposes a new calibration algorithm for the waveguide-penetration method. Reference materials with known electrical properties are fabricated in cylindrical shapes to fit into the holes in the waveguide and are used as calibration standards. The algorithm is formulated using the property of equal traces in similar matrices, and we show that at least two reference materials are needed to calibrate the system. The proposed algorithm yields a simpler means of calibration compared to TRL and is verified using measurements in the S-band. Also, the error sensitivity coefficients are derived. These coefficients give valuable information for the selection of reference materials.

In this paper, accuracy or error in permeability measurement using a combined microstrip line-coaxial conductor method was investigated. The measurement circuit used in this study is composed of a microstrip line (MSL) circuit and a grounded metal pipe with a center conductor passing through it coaxially. A sample is placed between the metal pipe and the center conductor. We evaluated the measurement accuracy for this measurement arrangement with electromagnetic simulation for the case where there are gaps between the sample and the holder. As a result, it has been shown that the normalized errors for this method have similar gap size dependence to the conventional coaxial method, but are about 10 to 20 percent greater than the coaxial method. With a view to improving the measurement accuracy, a correction method for the error is also discussed.

In this work, errors in a ferrite core permeability dispersion measurement using a microstrip line (MSL) method, where three kinds of MSL circuits are used, are evaluated by both an electromagnetic simulation technique and experiments. The computer simulated results have shown that although the measurement errors decrease according to the diameter of the winding wire which passes through a sample ferrite core becomes larger, that is the spacing between the wire and the core gets narrower, a certain amount of error still remains. In order to overcome this problem and improve the measurement accuracy, a metal pipe electrically connected to a ground plane for shielding is placed around the wire of the non-magnetic core circuit which is one of the three MSL circuits noted above.

Two-Thickness-Method (TTM) based on an open-ended coaxial probe was investigated with an emphasis on uncertainty analysis to perfect this technique. Uncertainty equations in differential forms are established for the simultaneous measurement of complex electromagnetic (EM) parameters in the systematical consideration of various error factors in measurement. Worst-case differential uncertainty equations were defined while the implicit partial derivation techniques were used to find the coefficients in formulation. The relations between the uncertainties and test sample's thicknesses were depicted via 3D figures, while the influence of the coaxial line's dimension on the measurement accuracy is also included based on the same analysis method. The comparisons between the measured errors and theoretical uncertainty prediction are given for several samples, which validate the effectiveness of our analysis.

Frequency-variation method (FVM), reported in [1], was further studied for simultaneously measuring the both complex permittivity and complex permeability by intentionally changing the test frequency to obtain different reflections. An enhanced coaxial-probe-based in-situ measurement system has been established. The spectral domain full-wave model is derived to take place of the quasi-static one. A novel coaxial probe is designed so that the one-port calibration could be performed with Agilent-supplied precise cal-kit instead of the liquid standard. Criterions for a right order of the interpolation polynomial used to approximate the frequency-dependent EM parameters; measures to reduce the residual mismatch errors and random error in reflection measurements and to suppress the ambiguities in solving the transcendent equation system were experimentally studied to resolve the problems and improve the accuracy in dispersive absorbing materials' test. Several typical dispersive absorbing coatings have been tested via FVM. The good comparison between the measured results and reference ones validate the feasibility of the proposed improved technique.

A compact, nonradiative, and easy fabricated left-handed material composed of planar circuit-type resonators in a cutoff waveguide is proposed. It is shown that the TE-type evanescent field is equivalent to the field in ε-negative material and the resonator works as a particle with negative permeability. The existence of a left-handed mode is ensured by a field distribution and a dispersion relation. After showing that the two constituents have an influence on the permittivity or the permeability of the material, on the basis of an idea of impedance, the material is matched to a conventional waveguide. Finally the material can be applied to a left-handed leaky-wave antenna.

Existence of a surface wave along the boundary between the semi-infinite materials, one of which is a free-space and the other is a material with either negative permeability or negative permittivity, is theoretically investigated. Surface waves exist in only limited combination of negative and positive signs of the material parameters. In addition, by analyzing the surface wave in a finite-thickness slab with negative permeability, its mode profile has been obtained for two different types of symmetry. From these results, the present paper predicts the possibility of a surface wave directional coupler based on a single slab transmission along its top and bottom surfaces.

A simplified model is set up to study the high frequency response in a thin film head, where two pieces of Fe-Al-N films are placed parallel to each other with opposite alternating external magnetic field applied. In this model, the frequency response of magnetic clusters is calculated by a micromagnetic model based on the Landau-Lifshitz-Gilbert equations, and the initial permeability of mesoscopic Fe-Al-N thin films is analyzed in a wide frequency region from 10 to 5000 MHz. The model of a soft magnetic thin film is built up on the ripple structure of the anisotropy field of magnetic clusters. The magnetization interaction between the two Fe-Al-N films is carefully computed to find its effect on the frequency response. The frequency response in a single mesoscopic Fe-Al-N thin film is carefully studied in advance.

The lossy magnetic composite material made from soft magnetic metal powder and rubber is widely used as an EMI countermeasure material, due to its higher magnetic loss than those of spinel ferrites in microwave frequencies. In this paper, we clarify the material characteristics by measuring the relative complex permeability r and relative complex permittivity r of two kinds of composite materials in microwave frequencies. Since the composite materials are anisotropic, both r and r are measured as diagonal tensors by utilizing extended S-parameter method. The results show that the imaginary part of r of flaky-powder composite exceeded the Snoek's limit for the spinel ferrites which has been reported so far. The measured r and r are partially compared with those measured by cavity resonator method, and good agreement is obtained.

Borehole radar is known as a powerful technique for monitoring of subsurface structures such as water flow. However, conventional borehole radar systems are operated in the frequency range lower than 100 MHz and the resolution is poor to measure a surface roughness and an inner structure of subsurface fractures directly. In order to monitor the water flow, these characteristics of subsurface fractures are important. We developed a polarimetric borehole radar system using dipole antennas and axial slot antennas and have found that this system can provide more information than conventional borehole radar. However, the relationship between the characteristic of subsurface fracture and the measured polarimetric radar information has not been clear. In this paper, we simulate electromagnetic wave scattering from subsurface fractures having a rough surface by Finite-Difference Time-Domain (FDTD) technique and discuss the relationship between a surface roughness of subsurface fracture and the polarimetric information. It is found that the subsurface fracture having strong cross-polarized components can be estimated to be rough surface fracture. The full polarimetric single-hole radar measurement was carried out at the Mirror Lake site, NH, USA. In this experiment, we found that subsurface fractures can be classified into some groups by an energy scattering matrix, and found that the subsurface fracture estimated to have a rough surface corresponds to that has higher water permeability.

It has been 15 years since we started producing the electric double-layer capacitors (also known as Super Capacitor) in 1978. Over the years we have introduced improvements that increased reliability and increased life. For example, after subjecting capacitors manufactured in 1984 and 1990 to load life tests (70, 5.5 V) for 2,000 hours, we discovered that the rate of change in capacitance (ΔC/C) of capacitors manufactured in 1990 was less than one-half that of capacitors manufactured in 1984. This shows that we have successfully increased the life of our electric double-layer capacitors. We conducted investigations regarding factors that contribute to volume of the electrolyte solution and better sealing properties. In the load life test, we observed that when the ratio of the weights of the electrolyte solution and the powdered activated carbon (hereinafter referred to as LB) was increased, the time it took before ΔC/C reached -30% was lengthened. This means that increasing LB also increases life. Furthermore, we also observed that when the gas permeability rate of the collector's rubber material was decreased in the load life test (70, 5.5 V), the time it took befor (ΔC/C) reached -30% was longer. Therefore life is dependent on the gas permeability rate (sealing property) of the collector rubber.