オンチップ設計に向けた磁性膜によるノイズ抑制機構に関する研究

Tohoku University石山和志課

Recent Topics in Electromagnetic Compatibility

Recent Topics in Electromagnetic Compatability discusses several topics in electromagnetic compatibility (EMC) and electromagnetic interference (EMI), including measurements, shielding, emission, interference, biomedical devices, and numerical modeling. Over five sections, chapters address the electromagnetic spectrum of corona discharge, life cycle assessment of flexible electromagnetic shields, EMC requirements for implantable medical devices, analysis and design of absorbers for EMC applications, artificial surfaces, and media for EMC and EMI shielding, and much more

Infrared receivers for low background astronomy: Incoherent detectors and coherent devices from one micrometer to one millimeter

The status of incoherent detectors and coherent receivers over the infrared wavelength range from one micrometer to one millimeter is described. General principles of infrared receivers are included, and photon detectors, bolometers, coherent receivers, and important supporting technologies are discussed, with emphasis on their suitability for low background astronomical applications. Broad recommendations are presented and specific opportunities are identified for development of improved devices

Development of Design Standards and Guidelines for Electromagnetic Compatibility and Lightning Protection for Spacecraft Utilizing Composite Materials

Preliminary design guidelines necessary to assure electromagnetic compatibility (EMC) of spacecraft using composite materials, are presented. A database of electrical properties of composite materials which may have an effect on EMC is established. The guidelines concentrate on the composites that are conductive but may require enhancement to be adequate for EMC purposes. These composites are represented by graphite reinforced polymers. Methods for determining adequate conductivity levels for various EMC purposes are defined, along with the methods of design which increase conductivity of composite materials and joints to adequate levels

Design Guidelines for Shielding Effectiveness, Current Carrying Capability, and the Enhancement of Conductivity of Composite Materials

These guidelines address the electrical properties of composite materials which may have an effect on electromagnetic compatibility (EMC). The main topics of the guidelines include the electrical shielding, fault current return, and lightning protection capabilities of graphite reinforced polymers, since they are somewhat conductive but may require enhancement to be adequate for EMC purposes. Shielding effectiveness depends heavily upon the conductivity of the material. Graphite epoxy can provide useful shielding against RF signals, but it is approximately 1,000 times more resistive than good conductive metals. The reduced shielding effectiveness is significant but is still useful in many cases. The primary concern is with gaps and seams in the material just as it is with metal. Current carrying capability of graphite epoxy is adequate for dissipation static charges, but fault currents through graphite epoxy may cause fire at the shorting contact and at joints. The effect of lightning on selected graphite epoxy material and mating surfaces is described, and protection methods are reviewed

A new measure for evaluating shielding performance of an equipment enclosure at frequencies above 1 GHz

The measure of shielding effectiveness (SE) and the related measurement techniques proposed by the current IEEE Standard 299 are only applicable for large screened enclosures having dimensions more than 2 m. To propose reasonable measures to assess the shielding performance of an equipment enclosure, together with the relevant measurement techniques, is the subject of this thesis. This work is informing the new developments in IEEE Standard 299. To coincide with the practical applications of most equipment enclosures, two measurement approaches distinguished by the location of the radiation source are considered in this thesis, and the measurement is performed in the radiating nearfield with test frequencies above 1 GHz. The contents inside the enclosure are stressed and involved in all the measurements. In the first measurement approach, to measure the enclosure’s ability to prevent the electromagnetic waves of internal contents from radiating outside to cause interference with nearby equipments, an emission source is -placed inside the enclosure and a receive antenna is placed outsic’j. A new measure shielding of radiating power (SRP) is proposed here, which consists of two parameters: the average shielding of radiating power (ASRP) and the enhancement factor E.F.g5lh. Two measurement environments: anechoic chamber and reverberation chamber are considered and compared. To avoid the huge measurement work in an anechoic chamber, the reverberation chamber is proposed as an ideal test environment to determine the ASRP, and the estimation of the enhancement factor E.F.gnh can be given directly based on statistic analyses on both measurement and simulation results. In the second measurement approach, to measure the enclosure’s ability to shield the internal contents against external interference, the enclosure is placed in a small reverberation chamber and illuminated by external electromagnetic field. Another new measure shielding of absorption cross section (SACS) is proposed here. However, measurement results indicate this measure has distinct advantages and disadvantages, so it is suggested prudently. Finally the first measure is proposed and reverberation chamber is suggested as the ideal test environment

Historical review of advanced materials for electromagnetic interference (EMI) shielding: Conjugated polymers, carbon nanotubes, graphene based composites

Electromagnetic (EM) interference (EMI) “an off-shoot of explosive growth of electronics and telecommunications” is becoming an alarming issue for modern society. It may degrade the EM device performance or may adversely affect human health. Recently, polymer based blends and composites have emerged as powerful solution for efficient suppression of EM noises; thanks to the unique combination of electrical, thermal, dielectric, magnetic and/or mechanical properties, possessed by them. This review focuses on the basics of EMI shielding/microwave absorption, various techniques for measurement of shielding effectiveness, theoretical aspects of shielding, governing equations. In addition, different strategies and potential materials for handling of EMI have also been discussed with special reference to polymer based blends and composites especially those based on carbon nanotubes (CNTs), graphene and intrinsically conducting polymers (ICPs)

Recent Trend in Electromagnetic Radiation and Compliance Assessments for 5G Communication

The deployment of the 5G networks will feature high proliferation of radio base station (RBS) in order to meet the increasing demand for bandwidth and also to provide wider coverage that will support more mobile users and the internet-of-things (IoT). The radio frequency (RF) waves from the large-scale deployment of the RBS and mobile devices will raise concerns on the level of electromagnetic (EM) radiation exposure to the public. Hence, in this paper, we provide an overview of the exposure limits, discuss some of the effects of the EM emission, reduction techniques and compliance assessment for the 5G communication systems. We discuss the open issues and give future directions