Summary of Research Project Results under JSPS FY2003
"Research for the Future Program"

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
5.Project Number 99P01501
6.Title of Project Studies on the Generation of Unintentional Electromagnetic-waves and their Propagation Mechanism

7.Project Leader
Name Institution,Department Title of Position
Hiroshi,Echigo Tohoku Gakuin University, Faculty of Engineering Professor

8.Core Members

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.

10.Key Words
(1)Unwanted EM wave radiation  (2)Transmission line modeling   (3)Radiation from bent wires
(4)Micro strip lines  (5)EM inter-coupling of lines   (6)Pulse radiation from a bent wire
(7)Transmission lines on dielectric materials  (8)ransmission lines with dielectric pipe   (9)Electromagnetic field pattern