Patent attributes
A magnetic field modem (26) includes an electro-magnetic radiation shielded (90) transmitter section (34) and a receiver section (36). The electro-magnetic radiation shielded (90) transmitter section (34) modulates data and transmits the data via a magnetic field through a radio frequency shield (20). The receiver section (34) receives the magnetic field through the radio frequency shield (20) and demodulates the data. The transmitter section includes an oscillator (40), a modulator (50), an amplifier (70), a magnetic transducer (80), and a non-ferrous magnetic shield (90). The oscillator (40) generates a carrier signal. The modulator (50) connects to the oscillator (40) and modulates the carrier signal with the data. The amplifier (70) connects to the modulator (50) and amplifies the modulated carrier signal. The magnetic transducer (80) connects to the amplifier (70) and converts the modulated carrier signal into a modulated magnetic signal. The non-ferrous magnetic shield (90) shields the magnetic transducer (80) and blocks emitted electro-magnetic radiation.