摘要:
In some embodiments, a radio frequency identification (RFID) reader with multiple antennas may determine the location of an RFID tag relative to the reader's antennas, by using a difference-in-time-of-arrival technique to triangulate on the RFID tag based on the difference in distances between the tag and each antenna. A given point in the signal from the RFID tag may provide a narrow point in time from which to make the calculations, while a common clock to the multiple receive paths may permit making accurate measurements of the difference in time of reception of that point at the different antennas. In some embodiments, movement of the RFID tag may be determined by calculating a series of locations over time.
摘要:
An embodiment of the present invention provides an apparatus, comprising an RF ID tag capable of reporting receiver signal strength indication, wherein the receiver signal strength may be indicated by an a RSSI byte included with an electronic product code (EPC) data packet. The EPC data packet may be in the standard SGTIN-64 EPC data format. Further, the RF ID tag capable of reporting signal strength may enable power control or beam steering.
摘要:
An RFID tag includes separate transmit and receive clocks. In at least one embodiment, the transmit clock frequency is adjusted based on an amount of power available to transmit a response signal to a reader.
摘要:
A transceiver includes a detuning circuit to generate an impedance mismatch in a receive signal path in response to a control signal provided by loop-control circuitry. The loop-control circuitry generates the control signal based on a comparison of detected peak signal levels in the receive signal path. In this way, high-power input signal levels in the receive signal path may be reflected back to an input of the receiver due to the impedance mismatch.
摘要:
A sensor may be used to detect a previous or current change of state, and the change may be reported by a radio frequency identification (RFID) tag. In some embodiments, the change may represent a broken security seal, which in turn may affect an electrical connection that can be sensed by the RFID tag during operation of the RFID tag.
摘要:
A digital storage medium (e.g., a CDROM, a DVD, a tape, etc.) has an integrated RFID tag to store information for use in controlling access to the data stored on the digital storage medium.
摘要:
A single antenna may be powered to illuminate or transmit to a receiver such as an RFID tag. That tag may then provide a responsive signal to a plurality of antennas, each of which are active. The signals from those antennas may be analyzed to determine which signal has the highest quality. This may be used to select a particular signal for future analysis or to select a particular antenna for use as both a transmission and reception antenna for future operations. For example, the antenna which provides the strongest signal may be utilized to further illuminate a given RFID tag.
摘要:
Embodiments of the present invention utilize two photodiodes on the same substrate, one illuminated monitor photodiode to monitor an optical beam out of a back facet (or back scattered) of a laser, and one non-illuminated reference photodiode to characterize in real time radio frequency (RF) parameters/performance to control extinction ratio and optical modulation amplitude of the laser beam.
摘要:
An optical-electronic interface may include a circuit substrate, an electrical component mounted on the substrate, an optical component mounted off the substrate, and a flexible interconnect having a first end electrically connected to the optical component and second end electrically connected proximate to the optical component. The electrical component may include electrical leads and the circuit substrate may include electrically conductive traces connected to the electrical leads. The second end of the flexible interconnect may be electrically connected directly to the electrical leads of the electrical component or directly to the electrically conductive traces at a position located proximate to the electrical component. A flexible optoelectronic interconnect may include a first and second dielectric layer, a signal layer with a signal trace disposed between the dielectric layers, ground plane layers on the first and second dielectric layers and a plurality of vias electrically coupling the first and second ground layers.
摘要:
A micromachined ultrasonic transducer (MUT) circuit, which has a MUT with a MUT membrane that can vibrate back and forth to transmit an ultrasonic wave, electrically controls the movement of the MUT membrane by controllably transferring energy to the MUT membrane, thereby allowing the MUT membrane to transmit substantially any desired ultrasonic wave.