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RF Shielding Tester

This is a work project.

The purpose of this project is to use low cost, USB hardware and free open-source software defined radio (SDR) to make test equipment for MRI room RF shielding. Specifically, to measure signal attenuation (in dB) by the room's RF shielding. The device should work for both 3T and 7T MRI scanners. Magnetic resonance imaging (MRI) works by generating and detecting signal in the radio-frequency range from the protons bound within the water (H20 -- two protons per molecule), fat, and macromolecules (proteins) in the body. The resonance frequency of water protons (1H2O) depends on the strength of magnetic field they are exposed to. This relationship between magnetic field and resonance radio-frequency is called the gyromagnetic ratio, and is 42.576 MHz/T (megahertz per Tesla) for 1H2O.

The operating frequency of a 3T scanner is 127.73 MHz, and the operating frequency of a 7T scanner is 298.03 MHz.

The first portion of this device is the HackRF One by Great Scott Gadgets: