Abstract: A method for use in a RFID reader, the method comprising providing an output signal from an amplifier of a transmitter, attenuating the output signal via a step attenuator, detecting and comparing the attenuated output signal to a reference value, and adjusting power to the amplifier until the attenuated output signal is substantially equal to the reference value. The attenuated output signal drives a local oscillator signal of a receiver thereby canceling noise generated by the transmitter in the receiver.

Abstract: An RFID circuit comprises an RF carrier signal source, a hybrid coupled to the RF carrier signal source operable to generate an in-phase and a quadrature phase component of the RF carrier signal, a switch coupled to the hybrid operable to pass one of the in-phase and quadrature phase components of the RF carrier signal to its output, and a mixer coupled to the output of the switch operable to multiply one of the in-phase and quadrature phase component of the carrier signal and a received modulated carrier signal and generate a baseband signal.

Abstract: An RFID circuit comprises an RF carrier signal source, and a hybrid coupled thereto operable to generate first, second and third phase-shifted RF carrier signals. The circuit further comprises first, second, and third mixers coupled to the hybrid each operable to multiply one of the first, second and third respective carrier signals and a backscattered modulated carrier signal and generate first, second and third baseband signals, respectively. The circuit further comprises first, second, and third delay lines respectively coupled to the first, second, and third mixers and operable to generate first, second and third delayed baseband signals. The circuit further comprises logic coupled to the first, second, and third mixers and the first, second, and third delay lines and operable to detect substantially simultaneous data transitions in at least two of the first, second, and third baseband signals, and generating a reconstructed signal having a data transition in response thereto.

Abstract: An RFID circuit comprising an RF carrier signal source, a hybrid coupled to the RF carrier signal source operable to generate first and second phase-shifted RF carrier signals, first and second mixers coupled to the hybrid each operable to multiply a respective one of the first and second carrier signals and a received backscattered modulated carrier signal and generate first and second baseband signals, respectively, and first logic coupled to the first and second mixers operable to select one of the first and second baseband signals having a larger amplitude as a demodulated RFID output signal.

Abstract: An RFID circuit comprises an RF carrier signal source, a hybrid coupled to the RF carrier signal source operable to generate an in-phase and a quadrature phase component of the RF carrier signal, a switch coupled to the hybrid operable to pass one of the in-phase and quadrature phase components of the RF carrier signal to its output, and a mixer coupled to the output of the switch operable to multiply one of the in-phase and quadrature phase component of the carrier signal and a received modulated carrier signal and generate a baseband signal.

Abstract: In one aspect, the present invention provides an air coil 20. The air coil 20 may be made from a strip of electrically conductive material 22 which has an insulating material overlying it. For example, the conductive material may comprise copper. The strip 22 is wound into a coil to perform a plurality of windings. The insulating material electrically insulates each of the windings from adjacent ones of the windings.

Abstract: The present invention discloses an electromagnetic device which includes a magnetic flux producing apparatus for producing a magnetic flux path loop. The magnetic flux producing apparatus preferably comprises a magnetic core 20 surrounded by electrical windings 22. A strip of electrically conductive material 24 is disposed such that it passes through the magnetic flux path loop and overlies the windings 22. The strip 24 has a width which is substantially greater than its thickness. The device may further include an antenna 16 which is electrically coupled to the strip 24.

Abstract: In one aspect, the present invention provides an air coil 20. The air coil 20 may be made from a strip of electrically conductive material 22 which has an insulating material overlying it. For example, the conductive material may comprise copper. The strip 22 is wound into a coil to perform a plurality of windings. The insulating material electrically insulates each of the winding from adjacent ones of the windings.

Abstract: In one aspect, the present invention provides an integrated inductor and capacitor 20 which can be used as the inductive portion of a resonant circuit and the energy accumulator for a identification system transponder. In a first embodiment, the integrated inductor and capacitor component 20 may include first and second strips of electrically conductive material 22 and 26, for example aluminum. The first and second strips 22 and 26 are wound in a coil 20 to form a plurality of windings. Each winding is electrically insulated from adjacent ones of the windings by insulators 24 and 28. The component can be bonded to a transponder chip.

Abstract: An apparatus including an object 10 associated with a contactless, electronic identifier is disclosed herein. In one example, the object 10 is a trash bin. This object 10 is formed from a non-conductive material. A single-loop antenna 14 is disposed adjacent the object 10. An impedance transformer 18 which is matched to the single-loop antenna 14 is used to generate a desired inductance. A transponder 12 is also disposed near to and associated with the object 10. The transponder 12 is coupled to the antenna 14 through the impedance transformer 18.