Abstract: A testing system and method for testing glass-mounted RFID tags such as tags mounted on vehicle windows. A testing carrier for use in a test chamber simulates the effect on the tag of the mounting glass. The test chamber and carrier are calibrated by first mounting the tag on the test carrier and making sensitivity measurements and then mounting the tag on glass that is representative of the actual production environment. Comparisons are made between the two measurements and calibration factors are derived to compensate for differences between the actual mounting glass and the test carrier. The test carrier is designed to provide uniform pressure against the tag to minimize any distortions that would alter the sensitivity of the tag.

Abstract: A testing system and method for testing glass-mounted RFID tags such as tags mounted on vehicle windows. A testing carrier for use in a test chamber simulates the effect on the tag of the mounting glass. The test chamber and carrier are calibrated by first mounting the tag on the test carrier and making sensitivity measurements and then mounting the tag on glass that is representative of the actual production environment. Comparisons are made between the two measurements and calibration factors are derived to compensate for differences between the actual mounting glass and the test carrier. The test carrier is designed to provide uniform pressure against the tag to minimize any distortions that would alter the sensitivity of the tag.

Abstract: An RFID tag includes a capacitor between the ASIC ground pin and the circuit ground. The value of the capacitor is selected so that in the case of electrostatic discharge (ESD), the potential drop is primarily across the capacitor rather than the ASIC. Thus, the ASIC is protected against ESD.

Abstract: RFID tags are disclosed having uniform electronics assemblies, but which fit into a variety of housings. This manufacturing technique allows for high volume production of tag electronics while keeping the mounting means adaptable to a variety of support structures. This ability to host a variety of support structures is important at least in the field of RFID tags for motorcycles, because motorcycles have varying configurations and no one tag would fit all motorcycles.

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: 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: 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 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: A device that communicatively couples a number of transmitters and receivers to a number of antennas. The device includes transmit ports each of which may be connected to a respective transmitter, receive ports each of which may be connected to a respective receiver, and antenna ports each of which may be connected to a respective antenna. One coupling unit has inputs connected to each transmit port and outputs to respective antenna ports for combining individual transmit signals received at each transmit port to form a combined transmit signal, and outputs the combined transmit signal to each respective antenna port. A second coupling unit has inputs connected to respective antenna ports and outputs to each receive port for combining individual receive signals from each respective antenna port to form a combined receive signal, and outputs the combined receive signal to the receive ports.

Abstract: A single port antenna connector assembly, mateable with either a retractable antenna or a hardline connector, is provided. When the antenna connector is mated with the connector assembly, it engages a signal contact supplying an antenna signal. When the hardline connector is mated, it engages a signal contact supplying a conductive signal to test equipment, or to an auxiliary antenna. The signal contacts have different positions in the assembly, with each connector being differentiated to engage only its corresponding signal contact. In addition, the design of connector assembly permits the antenna to be withdrawn through the connector assembly, at least partially, past the unused test signal contact. The antenna has at least two positions so that the profile of the antenna can be reduced for either storage, or for lower gain operation when the device is in a standby mode of operation.

Abstract: A radio transceiver is provided for wireless communications, having an interface connection that is selectable between either an antenna or a cable interface. The radio transceiver is engaged to the antenna through an impedance matching network which translates the antenna impedance to match that of the radio transceiver. The radio transceiver can, alternately, be connected to external test equipment or performance enhancement equipment through the cable interface. Since the radio transceiver has the same impedance as most external test equipment, the antenna matching network is not required or used when test equipment is connected to the cable interface. In the present invention the cable interface at least partially disconnects the matching network whenever the cable interface is in use. Once the antenna has been disconnected, the impedance of the cable interface matches that of the radio transceiver.

Abstract: A control circuit which regulates an ac power output device. The control circuit is operatively connected to the ac power output and measures the ac signal with a diode to generate a control signal stimulus. A second diode is operatively connected to the power measuring diode so that the two diodes have the same voltage drops associated with the quiescent operation of the diodes. Quiescent voltage changes in the power measuring diode are canceled by the matching quiescent voltage change in the second diode. In this manner, power measurement errors associated with diode quiescent voltage changes are minimized.