Low noise amplifier for MRI applications.

The operation of MRI is based on the nuclear magnetic resonance principle. Applying a static magnetic field followed by an oscillating magnetic pulse on a volume of tissue results in the emission of an electromagnetic field at the Larmor frequency. The purpose of this MQP is to design a dual stage low noise amplifier to amplify the radio frequency signals detected by the receiver coil. In order for the amplifier to function properly, it should have a noise figure of about 0.5dB, a gain of about 30dB, and a low input impedance. In addition, it should be unconditionally stable over a broad range of frequencies. Two amplifiers for 1.5T and 4.7T MRI scanners are designed and measurements were conducted to ensure their functionality