Signal/noise ratio optimization tuning system

摘要

A signal/noise ratio optimization tuning system, which can be used for tuning receiver antennas in Magnetic Resonance Imaging receiver systems, has a switch-controlled noise source means that is weakly coupled to the receiver antenna. The switch-controlled noise source switches a noise source between higher and lower power states at a predetermined frequency. A noise power meter means, which is synchronized to the switch-controlled noise source means, measures outputs of the receiver antenna. The noise power meter means measures the outputs of the receiver antenna when the noise source is switched between higher and lower power states and computes a ratio of the receiver antenna output with the noise source in the higher power state to the receiver antenna output with the noise source in the lower power state to obtain a noise power ratio. The tuning adjustment means is varied to maximize this noise power ratio.