Magnetic resonance apparatus.

摘要

The apparatus comprises an RF coil (9) which is tuned to a predetermined frequency and which is connected, via a connection circuit (14), to a transmission and/or receiving device (11, 13) for RF signals. In order to increase the bandwidth of the RF coil (9) without imposing restrictions in respect of the design and the construction of the coil, viewed from the RF coil the connection circuit (14) successively comprises the following elements: a first matching network (37) which is operative to transform an impedance connected to its output to a substantially lower value; a circuit (39) which has the properties of a transmission line whose effective length is substantially equal to an integer number of times one half wavelength at the frequency whereto the RF coil (9) is tuned and whose characteristic impedance is substantially equal to the input impedance of the first matching network (37); a second matching network (41) which is operative to transform an impedance connected to its output to a substantially higher value.