Patent ID: 8760261

Claim:
A Radio Frequency Identification (RFID) reader circuit, the reader circuit comprising: a Radio Frequency (RF) power amplifier coupled to an output of a RF source; an amplitude and phase adjustor module coupled to an output of the RF power amplifier; a signal combiner module coupled to an output of the amplitude and phase adjustor module; and a low noise amplifier coupled to an output of the signal combiner module, wherein the amplitude and phase adjustor module is configured to provide a carrier cancellation signal to the signal combiner module, wherein the amplitude and phase adjustor module comprises: two phase-shift networks coupled in parallel to the output of the RF power amplifier, and two adjustable digital attenuators, each coupled to an output of one of the phase-shift networks, wherein each one of the phase-shift networks provides a +90 ° shift on a first bath and a −90° shift on another path, the paths being selectively coupleable to the adjustable digital attenuator associated therewith.