A decoupling circuit for a radio frequency (RF) surface coil having a
plurality of tuning capacitors includes at least two decoupling points
and a DC source coupled to the at least two decoupling points. Each
decoupling point is associated with one of the plurality of tuning
capacitors. Each decoupling point includes a decoupling inductor
connected in parallel with a tuning capacitor, a diode connected in
series with the decoupling inductor and in parallel with the tuning
capacitor, a resistor connected in parallel with the diode and at least
one isolating inductor connected between the resistor and the diode to RF
isolate the resistor. The value of the resistor in each decoupling point
is selected to maintain a high quality factor (Q) of the RF surface coil
and to reduce the switching speed of the decoupling circuit.