Abstract: A system and method for generating a rectified signal in a RFID tag. An alternating signal is received by the RFID tag, and a first phase of the alternating signal is coupled to a gate and to a first non-controlling terminal of a first switching transistor. The non-controlling terminal of the first switching transistor is one of a source and a drain of the first switching transistor. A first bias voltage is applied between the first non-controlling terminal and the gate of the first switching transistor and a rectified voltage is received between the first non-controlling terminal and a second non-controlling terminal of the first switching transistor.

Abstract: Rogue RFID readers are detected by listening to communication between rogue reader and a tag, capturing an identifier associated with the tag from the communication by the reader or by the tag, and checking the captured identifier to determine whether it is a result of a command from another legitimate reader. Audible or visible alerts may be issued, flags may be set, or messages transmitted to an administrator upon determining the operation of the rogue RFID reader. Based on the alert(s) affected tags or the rogue reader may be jammed or an effect of the illegal transmission by the rogue reader may be reversed or tags replaced.

Abstract: RFID tags, ICs for RFID tags, and methods are provided. In some embodiments, an RFID tag includes a memory with multiple sections, and a processing block. The processing block may map one of these sections, or another of these sections, for purposes of responding to a first command from an RFID reader. As such, an RFID tag can operate according to the data stored in the section mapped at the time. In some embodiments, a tag can even transition from mapping one of the sections to mapping another of the sections. This can amount to the tag exhibiting alternative behaviors, and permits hiding data on the tag.

Abstract: A method of calibrating an oscillator within a Radio-Frequency Identification (RFID) tag includes storing a plurality of calibration values within a memory structure. Each of the calibration values corresponds to a respective oscillation frequency of the oscillator. A selected calibration value is selected from the plurality of calibration values stored, according to a first selection criterion. The oscillator is then calibrated in accordance with the selected calibration value.

Abstract: A precursor for a Radio Frequency Identification (RFID) tag includes a conductive lead frame with at least three segments, an RFID Integrated Circuit (IC) with at least two antenna terminals, and at least two jumpers. The RFID IC is mounted on at least one of the segments. The antenna terminals are electrically coupled to at least two of the segments, and the jumpers electrically couple the segments such that the coupled segments form a two-turn coil between the antenna terminals of the RFID IC.

Abstract: RFID tags are configured to adjust their clock frequency in order to meet predefined limits for reply frequencies to conserve tag power. A deviation of computed tag reply frequency from a reader commanded reply frequency is used to determine an adjustment to the tag clock frequency. The tag clock frequency may be adjusted during backscatter and restored once backscattering is completed.

Abstract: RFID tags are assembled through affixing an antenna to an integrated circuit (IC) by forming one or more capacitors coupling the antenna and the IC with the dielectric material of the capacitor(s) including a non-conductive covering layer of the IC, a non-conductive covering layer of the antenna such as an oxide layer, and/or an additionally formed dielectric layer. Top and bottom plates of the capacitor(s) are formed by the antenna traces and one or more patches on a top surface of the IC.

Abstract: RFID reader systems, readers, components, software and methods for causing RFID tags to backscatter a combination made from at least portions of a first code and a second code stored in tag memory, without transmitting any commands in the interim. In a number of embodiments, therefore, a separate command does not have to be sent for also reading the second code, thereby saving time in inventorying the tags. Plus, the combination can enable reading tag codes during tag manufacturing that are not otherwise readily available to read in the field.

Abstract: Radio frequency identification (RFID) tags selected for inventorying using combination of preselect and/or post select criteria. The selection commands can be for selecting according to a tag memory content, by invoking the mask address or by comparing other tag characteristics. Selection criteria can be determined locally at a modem block of a reader or provided to the modem block by higher layers of the reader. Tags meeting the selection criteria are reported to the higher layers for further actions. Some tags may be held while waiting for instructions from the higher layer block(s).

Abstract: RFID tags and chips for RFID tags store a first code and a second code in memory. They are capable of backscattering a combination made from at least portions of the first code and the second code, without receiving any commands in the interim. In a number of embodiments, therefore, a separate command does not have to be sent for also reading the second code, thereby saving time in inventorying the tags. Plus, the combination can enable reading tag codes during tag manufacturing that are not otherwise readily available to read in the field.

Abstract: RFID readers, reader systems, and methods are provided that utilize smart antenna switching. A first signal is transmitted from a first antenna estimating presence of tags within the antennas field of view. If fewer than a predefined number of tags are estimated, the system switches to a second antenna. Otherwise, the tags found in the field of view of the first antenna are inventoried before switching to the second antenna.

Abstract: RFID reader and methods of operating an RFID reader are provided to limit or prevent the issuing of confidential information such as encryption keys, passwords, shared secrets, and the like to RFID tags if a reader is not authorized. The reader may determine its authorization status based on a self-check, information from another reader, or information from a controller, and limit an operational aspect of itself or for communication with the tags.

Abstract: The present disclosure provides a power rectifier for a Radio Frequency Identification tag circuit. The rectifier is constructed from a pair of complementary MOS transistors. Gates of the transistors have predetermined voltages applied to them. The applied voltages bias the transistors to near their active operating region. During the same time additional control signals are applied to the gates of the transistors, the control signals are synchronous, but out of phase, with each other.

Abstract: A semiconductor chip for an RFID tag is described. The semiconductor chip including wireless transceiver and processing block circuitry to receive and put into effect a wirelessly received instruction encoded in a TUNE command. The instruction commanding the semiconductor chip to perform at least one specific act. The semiconductor chip having circuitry to perform the at least one specific act. The circuitry being coupled to the processing block. The circuitry and its corresponding specific act identified by at least one of the following: enablement circuitry to turn a sub-circuit within the semiconductor chip on; disablement circuitry to turn a sub-circuit within the semiconductor chip off; current bias circuitry to alter a bias current within a sub-circuit of the semiconductor chip; voltage bias circuitry to alter a bias voltage within a sub-circuit of the semiconductor chip; threshold adjustment circuitry to adjust a threshold within a sub-circuit of the semiconductor chip.

Abstract: The present disclosure provides a Radio Frequency Identification (RFID) reader software structure and method. A functionality of a reader engine is extended, enabling it to communicate via an extended standard Application Programming Interface (API) with an application software. The extended functionality supports a Partner Service Module that resides in the reader, thus allowing at least one of its Partner Software Functions to communicate with the application software over a single connection.

Abstract: RFID tag responses are detected by an RFID reader system. The tag response may be detected based on a reference measurement during a tag silent period and another one during the tag response. This helps determine whether a slot is empty or occupied, in a slotted aloha algorithm. The result is reported to the Q-algorithm for a better decision.

Abstract: The present disclosure provides examples of a voltage regulator for a Radio Frequency Identification tag circuit. The voltage regulator includes a pair of native transistors. A first native transistor is coupled to a reference voltage and biased to saturation. A resistive element coupled between the gate and the drain of the transistor ensures a sufficient voltage difference between the source and the drain of the first native transistor. The second native transistor, with a gate coupled to the gate of the first native transistor, outputs a regulated voltage.

Abstract: RFID reader systems, readers, components, software and methods cause RFID tags to reply using changed reply timing. In a number of embodiments, this timing change is achieved by causing a custom timing command to be transmitted to a tag. In some embodiments, the changed reply timing affects an amount of delay before a tag backscatters a reply.

Abstract: Interfacing is provided, to a utility of an RFID reader. The utility causes the RFID reader to instruct tags to reply using changed reply timing. The interfacing enables an agent to control the utility, for installing it, configuring it, enabling it, disabling it, or operating it. In a number of embodiments, the tag timing change is achieved by causing a custom timing command to be transmitted to a tag. In some embodiments, the changed reply timing alters the delay before a tag backscatters a reply.

Abstract: RFID tag circuits, tags, and methods are provided for receiving a partial-kill command. In response to receiving such a command, the tag circuit or tag becomes partially killed. This means that one or more but not all of its memory functions become disabled.