Title :
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
fDate :
8/1/1994 12:00:00 AM
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;
Journal_Title :
Electromagnetic Compatibility, IEEE Transactions on
