The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 20, 2001
Filed:
Sep. 17, 1999
Michael Burl, Chagrin Falls, OH (US);
Thomas Chmielewski, Willoughby Hills, OH (US);
William O. Braum, Twinsburg, OH (US);
Picker International, Inc., Highland Heights, OH (US);
Abstract
A multi-channel balun (,) blocks stray RF current from flowing on shield conductors of coaxial RF cables of a magnetic resonance apparatus. The balun comprises a parallel combination of an even number of helical coils of shielded transmission cable (L,L,L,L,L,L,) wound in alternate directions such that voltages iduced by their external RF fields cancel. One capacitor (C,C,C,) is connected in parallel symmetrically with each pair of helical coils, with trim capacitors (C,C,) fixed in the coil plug (,) to retune the balun as required. The multi-channel balun (,) accommodates magnetic resonance systems with an odd or even number of channels without requiring shielding. Preferably, the balun (,) is constructed on a single circuit board in a close-packed relationship that is compact and space efficient, yet provides better decoupling from the transmit field.