Aperture excitation of electrically large, lossy cavities

Author

Hill, David A. ; Ma, Mark T. ; Ondrejka, Arthur R. ; Riddle, Bill F. ; Crawford, Myron L. ; Johnk, Robert T.

Author_Institution

Div. of Electromagn. Fields, Nat. Inst. of Stand. & Technol., Boulder, CO, USA

Volume

36

Issue

3

fYear

1994

fDate

8/1/1994 12:00:00 AM

Firstpage

169

Lastpage

178

Abstract

We present a theory based on power balance for aperture excitation of electrically large, lossy cavities. The theory yields expressions for shielding effectiveness, cavity Q, and cavity time constant. In shielding effectiveness calculations, the incident field can be either a single plane wave or a uniformly random field to model reverberation chamber or random field illumination. The Q theory includes wall loss, absorption by lossy objects within the cavity, aperture leakage, and power received by antennas within the cavity. Extensive measurements of shielding effectiveness, cavity Q, and cavity time constant were made on a rectangular cavity, and good agreement with theory was obtained for frequencies from 1 to 18 GHz

Keywords

Q-factor; magnetic shielding; 1 to 18 GHz; Q theory; SHF; UHF; absorption; aperture excitation; aperture leakage; cavity Q; cavity time constant; electrically large lossy cavities; incident field; lossy objects; measurements; plane wave; power balance; random field illumination; received power; rectangular cavity; reverberation chamber illumination; shielding effectiveness; uniformly random field; wall loss; Absorption; Antenna measurements; Antenna theory; Aperture antennas; Frequency measurement; Lighting; Q measurement; Receiving antennas; Reverberation chamber; Time measurement;

fLanguage

English

Journal_Title

Electromagnetic Compatibility, IEEE Transactions on

Publisher

ieee

ISSN

0018-9375

Type

jour

DOI

10.1109/15.305461

Filename

305461