Wireless transmitter
A magnetic field tolerant amplifier having an amplifier stage, a differential to single-ended output amplifier stage and a first and second delay line. In another embodiment the invention relates to a magnetic gradient cancellation delay line including two coils connected in series at a junction and non-inductively wound to cancel induced currents from magnetic gradient. In another embodiment the invention relates to a patient lead including a flexible circuit substrate having a flexible conductor having distributed impedance. In still yet another embodiment the invention relates to a wireless transceiver system including an RF cancellation delay line; a differential amplifier stage; a differential to single ended output amplifier stage; an A/D converter; an RF transceiver and an antenna.
1. A wireless transceiver system for use in a time varying radio frequency field, said time varying radio frequency field having a predetermined frequency, the wireless transceiver system comprising:
a first and second radio frequency delay line, each of said first and second radio frequency delay lines having a delay line output terminal and a delay input terminal, said delay line input terminal of each radio frequency delay line configured for connection to an input signal source, said input signal source having an input signal comprising a signal of interest and a component resulting from the effects of a radio frequency field;
a radio frequency cancellation delay line circuit comprising:
the first and second radio frequency delay lines,
each radio frequency delay line output terminal in communication with a respective one of a pair of radio frequency cancellation delay line circuit output terminals and each radio frequency delay line input terminal in communication with a respective one of a pair of radio frequency cancellation delay line circuit input terminals;
an amplifier stage, said amplifier stage comprising a pair of differential input terminals and a pair of differential output terminals; each of said pair of differential input terminals of said amplifier stage in electrical communication with a respective output terminal of said pair of radio frequency cancellation delay line stage output terminals;
a differential to single ended output amplifier stage, said differential to single ended output amplifier stage comprising a pair of differential input terminals and an output terminal, each of said differential input terminals of said differential to single ended output amplifier stage in electrical communication with a respective one of said differential output terminals of said amplifier stage;
an analog to digital converter having an output terminal and having an input terminal, said input terminal of said analog to digital converter in electrical communication with said output terminal of said differential to single ended output amplifier stage;
an radio frequency transceiver having an output terminal and having an input terminal, said input terminal of said radio frequency transceiver in electrical communication with said output terminal of said analog to digital converter; and
an antenna in electrical communication with said output terminal of said radio frequency transceiver,
wherein each said first and second radio frequency delay lines is configured to produce an 180 degree phase shift at the predetermined frequency in the component of said input signal resulting from the effects of the radio frequency field at said radio frequency delay line output terminal to thereby cancel the 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.
2. The Wireless transceiver system of claim 1 further comprising a processor in electrical communication with said analog to digital converter and said transceiver.
3. A wireless transceiver system for use in a time varying radio frequency field, said time varying radio frequency field having a predetermined frequency, the wireless transceiver system comprising:
a first transceiver sub-system comprising:
a first and second radio frequency cancellation delay line each of said first and second radio frequency delay lines having a delay line input terminal and a delay line output terminal, said delay line input terminal configured for connection to an input signal source, the input signal source having an input signal comprising a signal of interest and a component resulting from effects of a radio frequency field;
an amplifier stage, said amplifier stage comprising a pair of differential input terminals and a pair of differential output terminals; each of said pair of differential input terminals of said amplifier stage in electrical communication with a respective output terminal said pair of radio frequency cancellation delay line output terminals;
a differential to single ended output amplifier stage, said differential to single ended output amplifier stage comprising a pair of differential input terminals and an output terminal, each of said differential input terminals of said differential to single ended output amplifier stage in electrical communication with a respective one of said differential output terminals of said amplifier stage;
an analog to digital converter having an output terminal and having an input terminal, said input terminal of said analog to digital converter in electrical communication with said output terminal of said differential to single ended output amplifier stage;
a radio frequency transceiver having an output terminal and having an input terminal, said input terminal of said radio frequency transceiver in electrical communication with said output terminal of said analog to digital converter;
an antenna in electrical communication with said output terminal of said radio frequency transceiver; and
a second transceiver subsystem comprising;
a second radio frequency transceiver having an input terminal and an output terminal; and
an antenna in electrical communication with said input terminal of said second radio frequency transceiver,
wherein each said first and second radio frequency delay lines is configured to produce an 180 degree phase shift at the predetermined frequency in the component of said input signal resulting from the effects of the radio frequency field at said radio frequency delay line output terminal to thereby cancel the 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.