双超低磁矩快恢复二极管用于MRI的应用 DUAL ULTRA LOW MAGNETIC MOMENT FAST DIODES FOR MRI APPLICATIONS
The is the first MRI switching diode module, designed to optimize performance and reduce assembly labor, cost, and polarity errors. There are two principle applications for which the UMX9989AP modules are intended: 1 MRI receiver protection from high RF energy fields, including long RF pulses and RF spike pulses present in most MRI machines. The UMX9989AP acts as a passive protector limiter for the MRI receiver’s LNA. The diode assembly exhibits extremely low insertion loss, both in the “on” state high power present and the “off” state receiver power present so the Receiver’s Noise Figure is not increased by the protector circuit. 2 Passive switching of surface coil detuning and blocking circuits. In this case, the flow of loop current during transmitter pulse turns on the diodes, without a switch driver.