• George M. Kunkel


The attenuation factors associated with the penetration of an electromagnetic wave into and through a shielding barrier (as predicted by the accepted theory of shielding) are presented. The accepted theory consists of the use of (1) Maxwell’s equations and (2) the analogy between transmission lines (as predicted by wave theory) and the penetration of a wave through a shielding barrier. The use of the analogy is the method of choice by the electronic industry. This method is fully analyzed, where four (4) factual statements are presented that illustrate that the use of the analogy yields highly inaccurate results. A theory of shielding is presented (which is proven to be accurate through test). The theory of the penetration of a wave through a seam or EMI gasketed seam is presented.


Shielding theory Shielding practice - Maxwell’s equations Wave theory Circuit theory EMI gasket Electromagnetic waves EM waves Shielding effectiveness Displacement current Shielding barrier E field shielding H field shielding 


  1. 1.
    Halme L, Annanpalo J (1992) Screening theory of metallic enclosures. IEEE, EMC International Symposium, Anaheim, CAGoogle Scholar
  2. 2.
    Sokolnikoff I, Redheffer R (1958) Mathematics and physics in modern engineering. McGraw HillGoogle Scholar
  3. 3.
    Frederick Research Corp. (1962) Handbook of Radio Frequency Interference, vol 3, (Methods of Electromagnetic Interference Suppression). Frederick Research Corp., Wheaton, MDGoogle Scholar
  4. 4.
    Ott HW (1976) Noise reduction techniques in electronic systems, Wiley, New YorkGoogle Scholar
  5. 5.
    Broaddus Al, Kunkel G (1992) Shielding effectiveness testing of 1.0 Ohm aluminized Mylar, IEEE, EMC International Symposium, Anaheim, CAGoogle Scholar
  6. 6.
    Hallen E (1962) Electromagnetic theory. Wiley, New YorkGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2020

Authors and Affiliations

  • George M. Kunkel
    • 1
  1. 1.Spira Manufacturing CorporationSan FernandoUSA

Personalised recommendations