|1.Research Institution||Tohoku Gakuin University|
|2.Research Area||Physical and Engineering Sciences|
|3.Research Field||Reduction of Electromagnetic Noise Levels|
|4.Term of Project||FY 1999 - FY 2003|
|6.Title of Project||Studies on the Generation of Unintentional Electromagnetic-waves and their Propagation Mechanism|
|Name||Institution,Department||Title of Position|
|Hiroshi,Echigo||Tohoku Gakuin University, Faculty of Engineering||Professor|
|Names||Institution,Department||Title of Position|
|Tkayasu,Shiokawa||Tohoku Gakuin University, Faculty of Engineering||Professor|
|Yahachi,Kuboyama||Ashikaga Institute of Technology, Faculty of Engineering||Professor|
|Tkashi,Nkaamura||Gifu University, Faculty of Engineering||Professor|
9.Summary of Research Results
This project group focused to the analysis of electromagnetic (EM) noise radiation and propagation, especially from the circuit boards of digital systems. To promote the research works more efficiently, some realistic subjects were selected as followed, and desirable results were obtained.
(1)Quantitative analyses of EM wave radiation from the bent portion of the transmission lines and FDTD analyses of micro strip lines with bend: gave the results that the bent portion causes the radiation and the propagation loss. On micro strip lines, line-width resonances increase the radiation for higher frequency range corresponding to the higher harmonic components of digital signal as of several GHz. Suppress techniques were proposed for the micro strip lines on PCB (printed circuit board).
(2)EM energy radiation from lines on the surface of dielectric materials: was found in the dielectric material side so that the EM waves are aparting from the transmission line into the material. A parallel 2-wire line with well-balanced mode causes less radiation.
(3)Propagation and radiation from a parallel two-wire line covered by some peaces of dielectric pipe: were measured changing the size and material constants. Even though small size lines with dielectric pipe, it radiates EM energy so efficiently that can be used as a high performance antenna for microwave range. The radiation comes from the structural resonance being given EM energy through the mode coupling by the parallel line.
(4)Analysis and measurement of the near field distributions around transmission lines: made clear that the EM wave energy propagating along the line radiates from the end portion and discontinuities. Precise measurements using the advanced instruments gave the motion of the EM waves near the line to understand the radiation and propagation phenomena.