Patent ID: 7124942

Claim:
A reader of an RFID system comprising: excitation circuitry for generating a higher voltage excitation signal; receiving circuitry for reading a lower voltage transponder signal; an antenna coupled with said excitation circuitry for transmitting said excitation signal and coupled with said receiving circuitry for receiving said transponder signal; and a low voltage signal stripping circuit included in said receiving circuitry coupled with said antenna for isolating said transponder signal from said excitation signal preliminary to said receiving circuitry reading said transponder signal, said low voltage signal stripping circuit comprising an inlet resistor, an amplifier, a feedback circuit and a DC shift voltage or a DC shift current source, wherein said feedback circuit has a first pathway including a first pair of clamping diodes aligned in series in a first direction, a second pathway including a second pair of clamping diodes aligned in series in a second direction opposite said first direction, and a third pathway including a feedback resistor having a resistance.