Abstract: A radio frequency identification (RFID) device is arranged for use with a remote interrogator unit. The RFID device comprises an integrated circuit configured to send, in response to a signal received from the remote interrogator unit or automatically, a responsive signal which includes identification information. A communication antenna is electrically coupled to the integrated circuit and is provided for wireless communication with the remote interrogator unit. At least one photovoltaic cell is provided for converting radiation into electrical energy and providing power to the integrated circuit. The photocell may be designed to form all or part of the RF antenna of the RFID device.

Abstract: Systems and methods for disabling transponders used in electronic toll collection or other RFID systems, wherein the transponders include an antenna and RFID circuitry. The transponders can be selectively disabled by releasably securing a disabling device having a metallic portion at an operative position over the antenna of the RFID system, whereupon the metallic portion is coupled to the antenna in such a manner as to disable the RFID circuitry so long as the disabling device is at the operative position. The RFID circuitry is arranged to be automatically enabled upon removal of the disabling device from the operative position.

Abstract: Payment systems and methods using wireless transponders in a community of retailers are disclosed. The disclosed systems and method include a community of retailers, an RFID transponder card, a number of readers for reading an identification number from the RFID transponder card when a subscriber carrying the card enters the community, a local computer in communication with the plurality of points of sale for receiving the identification number and associating the identification number with a subscriber account, and a Clearinghouse computer for validating the transponder card and notifying the local computer of the card's validation.

Abstract: When multiple readers for RF transponders have to be placed in close proximity, such as in adjacent lanes of a highway toll barrier, they can be set to operate at different frequencies. When signals from two adjacent ones of the readers interfere, the resulting signal includes interference terms whose frequencies equal the sum of the reader frequencies and the difference between the reader frequencies. To remove such interference terms while passing the desired terms, a tag includes a low-pass or other frequency-selective filter.

Abstract: Systems, tags and methods for disabling transponders used in electronic toll collection or other RFID systems, wherein the transponders include an antenna and RFID circuitry. The transponders can be selectively disabled by positioning (e.g., pivotably moving) a disabling member having a metallic portion to an operative position over the antenna of the RFID system, whereupon the metallic portion is coupled to the antenna in such a manner as to disable the RFID circuitry so long as the disabling member is at the operative position. The RFID circuitry is arranged to be automatically enabled upon removal of the disabling member from the operative position (e.g., pivoting the disabling member back to an inoperative position).

Abstract: A system has a read command signal that includes an Address field, Byte Data field, and Starting Address field. If the tag data read from the memory address identified by the Address field is the same as the Byte Data, the tag sends a response signal with Page Data read from the memory location identified by the Starting Address field and the tag ID. A write command signal includes an Address field, Byte Data field, Starting Address field, and Page Data field. If the tag data is the same as the Byte Data, the tag writes the data from the Page Data field to the memory location identified by the Starting Address field. Accordingly, data is read from and written to the tags in a single step, and the reader need not wait for the tag to respond with a tag ID before requesting that data be read from or written to that tag.

Abstract: A transponder includes a notch filter to suppress the 1300 MHz at minimal product cost increase. The notch filter utilizes a printed transmission line length adjusted to a correct length. This notch filter will connect to the antenna matching circuit at a junction between the antenna and an ASIC as a shunt component with high impedance (e.g., greater than 500 Ohms) at 915 MHz and low impedance (e.g., less than 10 Ohms) at 1300 MHz. Since the operating impedance of the junction is about 200 ohms, the 915 MHz signal from the antenna will feed the ASIC without any attenuation with a high shunt impedance component, while the 1300 MHz signal will be attenuated significantly by a low shunt impedance component. The transponder is applicable for all types of RFID tags (e.g., passive, semi-passive, active, read only, read-write, read first, tag-talk first) and is well suited for tags operating at radio frequencies, including microwave frequencies (e.g., 902 MHz to 928 MHz) in the U.S.

Abstract: An RFID tag having a non-volatile memory and a piezoelectric sensor. The piezoelectric sensor produces an electrical charge that momentarily supplies electrical power to the RFID tag when subjected to a mechanical force and the electrical power is sufficient to record data in the non-volatile memory. The piezoelectric sensor is affixed to an article such that an attempt to tamper with the article produces sufficient mechanical force on the piezoelectric sensor to record data evidencing the tampering in the non-volatile memory.

Abstract: An RFID tag for use in a vehicle for use in an electronic toll collecting system. The tag is capable of transmitting data to a tag interrogator indicating the occupancy status of the vehicle. In an embodiment, the tag has a user input and a visual and audible tag status indicator. The user input is used to change the occupancy status of the tag, wherein the occupancy status is a portion of a message sent by radio frequency to the interrogator when the vehicle passes through a toll area.

Abstract: A self-service vending unit allows a potential user of a toll transponder to buy the transponder without having to visit a customer-service facility. The vending unit automatically accepts payment, such as cash or a credit or debit card, and issues the transponder with a paid value. The vending unit communicates with a customer-service computer through a TCP/IP connection and allows the user to top off the value on the transponder and otherwise to manage the account.

Abstract: Systems and methods for disabling transponders used in electronic toll collection or other RFID systems, wherein the transponders include an antenna and RFID circuitry. The transponders can be selectively disabled by releasably securing a disabling device having a metallic portion at an operative position over the antenna of the RFID system, whereupon the metallic portion is coupled to the antenna in such a manner as to disable the RFID circuitry so long as the disabling device is at the operative position. The RFID circuitry is arranged to be automatically enabled upon removal of the disabling device from the operative position.

Abstract: A transponder includes a notch filter to suppress the 1300 MHz at minimal product cost increase. The notch filter utilizes a printed transmission line length adjusted to a correct length. This notch filter will connect to the antenna matching circuit at a junction between the antenna and an ASIC as a shunt component with high impedance (e.g., greater than 500 Ohms) at 915 MHz and low impedance (e.g., less than 10 Ohms) at 1300 MHz. Since the operating impedance of the junction is about 200 ohms, the 915 MHz signal from the antenna will feed the ASIC without any attenuation with a high shunt impedance component, while the 1300 MHz signal will be attenuated significantly by a low shunt impedance component. The transponder is applicable for all types of RFID tags (e.g., passive, semi-passive, active, read only, read-write, read first, tag-talk first) and is well suited for tags operating at radio frequencies, including microwave frequencies (e.g., 902 MHz to 928 MHz) in the U.S.

Abstract: The present invention discloses systems and methods for enabling cashless fueling transactions through the use of vehicle-based decal sticker RFID tags. The tags store a unique customer identification number as well as other frequent purchase information. When read by a reader installed at the fuel dispenser, the tag information is sent to the network host via the Point of Sale (“POS”) system, where it is linked to a customer's account for transaction processing and subsequent activation of the fuel dispenser. Several tags may be read by a single interface unit, avoiding the need to connect a tag reader to each fuel dispenser.

Abstract: A radio frequency identification (RFID) tag to be attached to an object to identify the object or a characteristic or feature thereof from data stored in the tag accessible by an RFID reader includes an application-specific integrated circuit (ASIC), configured to process signals from the RFID reader and return signals related to the stored data, an interdigit AC coupling circuit, in communication with the ASIC, a matching circuit, in communication with the interdigit AC coupling circuit and an antenna, in communication with the matching circuit, configured to receive signals from the RFID reader and transmit the signals related to the stored data. The interdigit AC coupling circuit and the matching circuit provide an AC coupling and a matching impedance between the ASIC and the antenna respectively.

Abstract: A tamper resistant electronic tag that wirelessly receives and transmits unique subscriber information to and from a transceiver so that financial transactions can occur quickly and seamlessly. In a preferred embodiment, the tag works in conjunction with a roadway toll booth and is mounted onto a flat interior surface of a vehicle, where it can receive and transmit electronic information to and from a toll booth. That allows a driver to pay the toll fee without having to stop his vehicle. The electronic tag includes a plastic protective card for carrying a circuit. The circuit includes an integrated circuit that is adhesively attached to the protective card. The protective card and circuit are then attached to the flat surface. When the protective card is removed, the integrated circuit is pulled off with the protective card while the rest of the circuit remains attached to the flat surface, thereby severing the circuit, and rendering it inoperable.

Abstract: A multi-protocol RFID interrogating system employs a synchronization technique (step-lock) for a backscatter RFID system that allows simultaneous operation of closely spaced interrogators. The multi-protocol RFID interrogating system can communicate with backscatter transponders having different output protocols and with active transponders including: Title 21 compliant RFID backscatter transponders; IT2000 RFID backscatter transponders that provide an extended mode capability beyond Title 21; EGO™ RFID backscatter transponders, SEGO™ RFID backscatter transponders; ATA, ISO, ANSI AAR compliant RFID backscatter transponders; and IAG compliant active technology transponders. The system implements a step-lock operation, whereby adjacent interrogators are synchronized to ensure that all downlinks operate within the same time frame and all uplinks operate within the same time frame, to eliminate downlink on uplink interference.

Abstract: In a protocol for preserving the privacy of communications between a RFID reader and a RFID tag, two distinct actions are taken. First, the reader and the tag must be mutually authenticated as being authorized participants in the communications. After that process is successfully completed, the authenticity of each authorized participant must be validated prior to each subsequent communication between reader and tag.

Abstract: A RFID tag to be attached to an object to identify the object or a characteristic or feature thereof from data stored in the tag accessible by a RFID reader includes a relatively flat structure having a small aperture antenna positioned on or proximate the tag in the form of a polygon having electrically conductive sides. The flat structure, which may be fabricated as a sticker or label, incorporates a small aperture antenna, such as a slot antenna, in the form of a polygon having electrically conductive sides. The polygon may be triangular, rectangular, square, elliptical, circular, or other polygonal figure depending on number of its plurality of sides. A constitutes the aperture of the antenna.

Abstract: A method and apparatus for maintaining sensitivity of a homodyne receiver over varying transmitter power levels is disclosed. The method includes adjusting output power levels of a transmitter driver. A bias supply voltage to the transmitter driver may be adjusted to adjust the output power levels. A control voltage to the transmitter driver may be adjusted to adjust the output power levels of the transmitter driver. A homodyne radio frequency tag reader may include the method.

Abstract: In a protocol for preserving the privacy of communications between a RFID reader and a RFID tag, two distinct actions are taken. First, the reader and the tag must be mutually authenticated as being authorized participants in the communications. After that process is successfully completed, the authenticity of each authorized participant must be validated prior to each subsequent communication between reader and tag.