Devices employing fast carrier cancellation and methods thereof

摘要

In one embodiment, a RFID reader circuit includes a RF power amplifier coupled to a coupler; an amplitude and phase adjustor module coupled to an output of the coupler; 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. In another embodiment, a RFID system includes a plurality of RFID tags; and at least one RFID reader, the at least one RFID reader comprising a RFID reader circuit, the circuit comprising: a RF power amplifier coupled to a coupler; an amplitude and phase adjustor module coupled to an output of the coupler; 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. Other systems, methods, and circuits are described as well.

主权项

1. 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.