Numerical Assessment of Electromagnetic Radiated Emissions from an UWB Radiators Located Inside Metallic Enclosures with Small Air-Flow Openings

Mohammed M Bait-Suwailm, Boudelliou A Boudelliou, Naser Al-Tarhuni


Shielding effectiveness of electronic devices and computing devices is  essential at design stages. Devices should pass electromagnetic interference/compatibility tests for certification purposes. In this paper, we investigate the electromagnetic radiation leakage from modern personal computers and mobile electronic devices due to an ultra-wide band source of noise. Openings and slots are always unavoidable in electronic devices, for instance openings in computers for air-flow and heat dissipation. Three different designs of enclosure’s covers with apertures are modeled for this purpose. The three covers cases comprise the use of rectangular arranged circular holes, hexagonal arranged circular holes, and square openings. For comparison purposes, a shielded enclosure with no openings is considered. The shielding effectiveness is numerically assessed here by capturing electric field strength that is modeled using probes located at two different distances, near- and far-away from the metallic enclosure.


Electromagnetic interference; Metallic enclosure; Radiated emissions; Shielding effectiveness; and UWB noise.

Full Text:



Bait-Suwailam M, Ramahi O (2012), Ultrawideband mitigation of simultaneous switching noise and EMI reduction in high-speed PCBs using complementary split-ring resonators. IEEE Transactions on Electromagnetic Compatibility 54(2): 389– 396.

Bait-Suwailam M, Alavikia B, Ramahi O (2014), Reduction of electromagnetic radiation from apertures and enclosures using electromagnetic bandgap strucutres. IEEE Transactions on Components, Packaging and Manufacturing Technology 4(5): 929-937.

Bait-Suwailam M, Al-Abri D, Teirab A, Jervase J, Nadir Z (2015), Electromagnatic Interference (EMI) Radiation from Airflow Openings in Personal Computers Shielding Enclosures: An Experemental Study. In the 8th IEEE GCC Conference & Exhibition 1-4.

Cerri G, De Leo R, Primiani V (1992), Theoretical and experimental evaluation of the electromagnetic radiation from apertures in shielded enclosure. IEEE Transactions on Electromagnetic Compatibility 34(4): 423–432.

Computer Simulation Technology (CST), Microwave Studio (MWS), 2014 [Online]. Available:

Federal Communications Commission Report, FCC 02-48 [Online]. Available:

Federal Communications Commission Revision Report (2002), Revision of Part 15 of the Commission's Rules Regarding Ultra-Wideband Transmission Systems. ET Docket 98-153.

Hao J, Jiang L, Gong Y, and Fan J (2016), Study of the shielding effectiveness of double rectangular enclosures with apertures excited by an internal source. Progress In Electromagnetics Research M, (47): 67-76.

Kubik Z, and Skala J (2013), Influence of the cavity resonance on shielding effectiveness of perforated shielding boxes. In the Proceedings of the 8th International Conference on Compatibility and Power Electronics 260–263.

Li M, Nuebel J, Drewniak J, DuBroff R, Hubing T, Van Doren T (2000), EMI from Airflow Aperture Arrays in Shielding Enclosures-Experiments, FDTD, and MoM Modeling. IEEE Transactions on Electromagnetic Compatibility 42(3): 265–275.

Liang J, Chiau C, Chen X, Parini C (2005), Study of a printed circular disc monopole antenna for UWB systems. IEEE Trans. On Antennas and Propagation 53(11): 3500-3504.

Lin L, Ramahi O (2002), Analysis and reduction of electromagnetic field leakage through loaded apertures. In the 2002 International IEEE Antennas and Propagation Society Symposium 102-105.

Ott H (1988), Noise Reduction Techniques in Electronic Systems, 2nd Edition, John Wiley and Sons Inc.

Pozar D (2011), Microwave Engineering., 4th edition, John Wiley & Sons, Inc., 284-287.

Qin J, Ramahi O, Granatstein V (2007), Novel planar electromagnetic bandgap structures for mitigation of switching noise and EMI reduction in high-speed circuits. IEEE Transactions on Electromagnetic Compatibility 49(3): 661– 669.

Sanders F (2001), Conversion of power measured in a circuit to incident field strength and incident power density, and corrections to measured emission spectra for non-constant aperture measurement antennas. Appendix C of NTIA Report 01-383.

Senthinathan R, John L (1994), Simultaneous Switching Noise of CMOS Devices and Systems, Norwell, MA: Kluwer.

Shahparnia S, Ramahi O (2004), Electromagnetic interference (EMI) reductionfrom printed circuit boards (PCB) using electromagnetic bandgapstructures. IEEE Transactions on Electromagnetic Compatibility 46(4): 580– 587.

Slyke T, Kuhn W, Natarajan B (2008), Measuring interference from a UWB transmitter in the GPS L1 band. In the IEEE Radio and Wireless Symposium 887-890.



  • There are currently no refbacks.

Copyright (c) 2018 Mohammed M Bait-Suwailm, Boudelliou A Boudelliou, Naser Al-Tarhuni

Creative Commons License
This work is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.


This journal and its content is licensed under a Attribution-NoDerivatives 4.0 International.

Flag Counter