摘要:
A multistage voltage multiplying circuit for single chip passive RF tags is provided, wherein the parasitic capacitance of the diodes of each stage of the voltage multiplying circuit is much less than the parasitic capacitance of the diodes of the preceding stage.
摘要:
A multistage voltage multiplying circuit for single chip passive RF tags is provided, wherein the parasitic capacitance of the diodes of each stage of the voltage multiplying circuit is much less than the parasitic capacitance of the diodes of the preceding stage.
摘要:
An apparatus, method, and system are provided for sending radio frequency (RF) power to RF transponders (RFID tags), wherein the frequency sent to the tags is changed very rapidly.
摘要:
An RFID interrogator has a receiver/transmitter architecture that accounts for the variation in tolerances of radio system electrical components. The RFID interrogator includes a memory in which is stored desired initial condition data of the receiver/transmitter architecture, and this initial condition data is used upon initialization of the RFID interrogator to define the operational condition of the RFID interrogator. Each individual RFID interrogator may contain unique initial condition data corresponding to the particular component tolerances of that radio system.
摘要:
An RFID tag may include an antenna substrate comprising a conductive layer etched or deposited to form an antenna, and a circuit substrate comprising a conductive layer etched or deposited to form a circuit, the antenna electro-magnetically coupled to the circuit. An RFID tag may be formed from an insert substrate comprising an insulative layer between two conductive layers, one of the conductive layers etched to form an antenna and the other conductive layer etched to form a circuit. The insert substrate may be received in an envelope formed by a label substrate, which may carry a pressure sensitive adhesive.
摘要:
An RFID reader directly controls computer network applications on the basis of information collected from an RFID tag. The RFID tag includes certain designated fields that identify a destination computer system and/or application program for data recovered from the RFID tag. The RFID reader can then distribute the collected information in a format and to a destination that is determined by the RFID tag, thereby eliminating the need for intermediary software programs or human operators to make such decisions about the distribution of information. This capability permits RFID tag information to be automatically collected and distributed to network applications for ultimate data processing and collection.
摘要:
The RFID interrogator further comprises a microcontroller module adapted to provide high level commands to the interrogator, a DSP module for processing received/transmitted data and controlling radio operations, and a radio module for transmitting and receiving RF signals to/from an RFID transponder. A first embodiment of the RFID interrogator comprises an RF carrier source providing a carrier signal, a processor providing an information signal, and plural modulation stages coupled to the RF carrier source for modulating the information signal onto the carrier signal using on/off keying modulation. The plural modulation stages are controlled in unison by control signals the said processor. The plural modulation stages provide dynamic range of greater than 25 dB between respective on and off states of the modulated signal. A second embodiment of the RFID interrogator comprises an RF carrier source providing a carrier signal, a modulator receiving the carrier source and modulating an information signal thereon to provide a modulated RF signal, and an amplification stage coupled to the modulator. The amplification stage splits the modulated RF signal into first and second components, and amplifies the first and second components separately. The first and second components are thereafter recombined. The split operation of the amplification stage provides a better match with the downstream transmission path than an individual amplifier. A third embodiment of the RFID interrogator comprises an RF carrier source providing a carrier signal, a demodulator combining a received signal with the RF carrier to provide a baseband signal, and an attenuator coupled to the demodulator for absorbing high frequency components of the baseband signal. The baseband signal further comprises in phase (I) and quadrature phase (Q) components. The high frequency components of the baseband signal pass through the high-pass filter to the resistor termination, where they are absorbed.
摘要:
A method of determining relative motion between a base station and an RF Tag is disclosed, wherein a property of the RF field at the position of the tag is determined at a first time and at a second time and is used to calculate the relative motion.
摘要:
An electronic beam steering technique for active arrays uses a single balanced diode mixer phase-locked loop connected between adjacent oscillators. Each oscillator has its own antenna that radiates energy into free space so the phase difference between oscillators determines the direction of the main radiating beam. An offset voltage added to the phase-locked loop controls the phase difference and thus the beam direction, providing over 100.degree. of adjustable phase difference between adjacent oscillators.
摘要:
A data collection device for reading barcodes, matrix codes, acoustical tags, radio frequency identifier (RFID) tags, and other data carriers. The data collection device includes components to determine an actual position of the data collection device with respect to a target data carrier. The data collection device further includes visual indicators to indicate the determined actual position relative to an optimal position of the data collection device relative to the target data carrier. The determined actual position can be at least one of an actual distance or an actual orientation of the data collection device relative to the target data carrier.