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The losses present in electrical machines are of major concern in modern industrial applications, very high speed drives, aerospace applications and the automotive industry. This paper presents the magnetic characterization of non-oriented steel sheets used for manufacturing permanent magnet synchronous machines and synchronous reluctance machines when these steel sheets are used at higher frequencies...
We present here our recent result on reducing the losses of a multiple-folded tunable microstrip line phase shifter based on liquid crystal (LC) for the regime of low microwave (MW) frequencies. It is shown that the insertion and return losses can be decreased through the minimization of the electromagnetic (EM) wave discontinuities in the folded microstrip line structure. Based on a modified 6-folded...
This work presents a study on the quality factor (Q-factor) of the passively temperature compensated CMOS-MEMS resonators through the collected material/experimental database and finite-element (FEM) simulation. By adapting an anchor-loss-free double-ended tuning fork (DETF) resonator design, the intrinsic material loss is expected to be the major loss mechanism in CMOS-MEMS resonators that limits...
Topic of this paper is the efficient modelling and simulation of state-of-the-art roof antennas employed for vehicles of the AUDI AG. In the investigated roof antenna, several services are joined within one antenna assembly covered by a common housing. To investigate whether the antenna fulfills all specifications concerning scattering parameters and radiation patterns, the antenna needs to be simulated...
A compact free-space setup is designed based on 90-degree off-axis parabolic mirrors and pyramidal horn antennas to cover a wide frequency range from 50 GHz to 500 GHz. A commercial VNA with frequency extenders is used to measure s-parameters and provide raw data to extract intrinsic material characteristics. The calibration process is simplified and a method is presented to extract both real and...
This paper investigates various aspects relative to dielectric sensor applications using stand-alone Voltage Controlled Oscillators (VCO) designed in advanced SiGe:C BiCMOS technology. Design, analysis and experimental verification of integrated dielectric sensors backed up by proper methodologies for characterization of material properties are presented. The proposed sensing system extracts frequency...
The method of the split cylinder resonator cavity (SCR) is used to characterize accurately and simultaneously in one temperature cycle, dimensional and electrical characteristics of the cavity and the electromagnetic properties of a dielectric material. To do this several modes are used, some to control the cavity and others to control the sample.
We present in this paper an electromagnetic model based on finite elements method for the characterization of dielectric samples with a near field microwave microscopy, this proposed model is a useful tool to determine for, a given microcopy probe, the minimum substrate thickness required to extract accurately the substrate relative permittivity and loss tangent. This paper proposes a practical application...
The characterization of materials by rectangular waveguide method usually requires a sample holder and a complicated procedure of preparing specimen in order to limit the air gaps between the specimen and the boundaries of the waveguide that will affect the accuracy of measurement. In this paper, we present a technique of complex permittivity measurement with a simple MUT (Material Under Test) preparation...
Electrically conductive adhesives are widely used in semiconductor technology. The focus of this work is set on Isotropic Conductive Adhesives (ICA) with a high amount of electrically conductive filler particles. The aim of this work is the material characterization of highly filled epoxy based die attaches materials by dynamic mechanical analysis (DMA) and relaxation experiments in order to derive...
A compact quasioptical setup is designed and optimized for material characterization in the frequency range 50 GHz to 500 GHz. The S-parameters are measured with a commercial Vector Network Analyzer (VNA) together with its mm/sub-mm frequency extenders. A simple practical calibration process is used to determine the diffracted waves on the material surface. A new method is proposed to extract the...
A THz TDS study of permittivity and conductivity properties of new variant of Yttria-stabilized-Zirconia (YSZ) produced using tape-cast method is reported. This study extends the frequency coverage of some of the previously published work. We find a general agreement with published results but the frequency gap in the mm-wave range needs to be measured more carefully before final conclusions on the...
Recent developments of third generation relaxor-PT piezoelectric type single crystals, Mn:PIN-PMN-PT, herald significant potential benefits to high power ultrasonic devices due to their high electro-mechanical coupling coefficient, low mechanical losses and increased temperature and electric field stability. This study reports on two power ultrasonic transducers, one based on piezocrystal and one...
Energy harvesting has been studied with great interest in recent years. Ambient vibration is a potential energy resource for low-power devices or electronic devices in extreme/remote area. Methods on enhance the energy conversion amount has been long been a main subject in energy harvesting field. The present study developed a precise model working under hybrid of electrical and mechanical excitations...
This paper describes test cells for electromagnetic characterization of materials in the frequency range from 5 Hz to 1000 MHz, which were developed at SIQ in the past 3 years as a part of EMINDA EMRP Project. Test cells are used for traceable measurements of different electromagnetic properties of bulk solid materials. Traceability of measurements is assured using characterized reference samples...
A simple method is presented to extract the material characteristics from the scattering parameters in the frequency domain. The method is based on “transmission” measurement data only and can give the complex permittivity and/or the absorption and refraction index via easy arithmetic operations with closed-form formulas. Therefore, a parametric error analysis will be feasible for metrological aspects...
Electromagnetic interference can hinder the operations of systems near the source of the interference. This paper details the process of using a nested reverberation setup in order to determine the absorptive effectiveness of several absorbing materials. Results show that the position of absorbing materials is inconsequential as long as they are placed outside of the working volume and away from wall...
Thin and flexible freestanding graphene nanoplatelets (GNPs)-based paper-like materials are fabricated and experimentally characterized to assess their employment as radiofrequency electromagnetic interference shields. Samples are obtained by vacuum filtration of ultrasonicated suspensions. Different suspensions are prepared by mixing either acetone/DMF or acetone/NMP and worm-like exfoliated graphite...
An efficient geometric optics (GO) method is successfully developed for the field uniformity (FU) analysis and converted to an in-house computer-aided design (CAD) software tool for anechoic chamber design. It can help anechoic chamber companies to select the right radio absorbing materials for a chamber to meet the desired specs. Simulation and measurement results are obtained and compared, and good...
Absorbing material has excellent attenuation ability to EM wave in high frequency. LC filter filled with absorbing material can realize high insert loss, above 80 dB, between 10 kHz and 110 GHz. This text first introduce the principle of absorbing wave of absorbing material, and then discussed eight compounded absorbing material's attenuation ability to high frequency EM energy. At last is the conclusion.
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