Patent ID: 7292038

Claim:
An MRI RF double-balanced double-tuned (DBDT) coil comprising 4n substantially identical adjacent ladder sections, where n is a small integer, on a substantially cylindrical dielectric coilform of diameter d F , for use in polarizing field B 0 , said DBDT coil further characterized as including means for orthogonal coupling at a lower frequency f L and a higher frequency f H , said ladder section further characterized as comprising serially connected ring sections at each end and rung sections axially there between, said rung sections further characterized as each comprising an axial inductive element having opposite rung ends and a rung capacitance C 1 series connected to each rung end, said ring sections further characterized as each comprising a ring inductive element L E and a ring trap, said C 1 further series connected to an adjacent ring inductive element, said ring trap comprising the parallel combination of a ring capacitance C E and a ring trap inductance L 1 , said ring trap further characterized as providing interconnection between adjacent ring inductive elements, said C E and said L 1 further characterized as having reactances of equal magnitudes at a frequency denoted as the ring-trap isolated resonant frequency f T , where said f T is greater than 0.5 f H but less than 1.1 f H .