Magnetic gradient cancellation delay line

摘要

The invention relates to a wireless transceiver system comprising an amplifier stage for use in a time varying radio frequency field, an A/D converter, an RF transceiver, a delay line, a differential to single-ended output amplifier stage, and an antenna. An input terminal of the RF transceiver is in electrical communication with an output terminal of the A/D converter. The antenna is in electrical communication with an output terminal of the RF transceiver. Each of differential input terminals of the differential to single-ended output amplifier stage is in electrical communication with a respective differential output terminal of the amplifier stage. A delay line output terminal of the delay line is in electrical communication with an input terminal of a pair of differential input terminals of the amplifier stage. The delay line input terminal of the delay line is configured for connection to an input signal source which has an input signal comprising a signal of interest and an interfering component caused by the radio frequency field. The delay line is configured to produce an 180 degree phase shift at a predetermined frequency in the interfering component of the input signal resulting from the effects of the radio frequency field at the delay line output terminal to thereby cancel the interfering component of the input signal resulting from the effects of the radio frequency field having the predetermined frequency and leave the signal of interest of the input signal substantially unaffected. An input terminal of the A/D converter is in electrical communication with an output terminal of the differential to single ended output amplifier stage.