摘要 |
<p>A coil assembly for transmitting or receiving radio frequency signals includes a coil, a capacitive tuning ring, a first capacitive shield, and a second capacitive shield. The coil includes axial conductors extending between first and second end regions and arranged about a longitudinal axis. The tuning ring is axially movable wherein an amount by which the tuning ring overlaps the plurality of axial conductors is adjustable. The first capacitive shield is axially movable relative to a first group of axial conductors wherein an amount by which the first capacitive shield overlaps the first group is adjustable. The second capacitive shield, offset ninety degrees from the first capacitive shield, is axially movable relative to a second group of axial conductors wherein an amount by which the second capacitive shield overlaps the second group is adjustable. The capacitive shields enable the coil to be quadrature balanced.</p> |