International Business Machines Corporation

Intermec IP Corporation

Other

Li-Cheng Richard Zai

Trieu Can Chieu

Harley K Heinrich

Paul Jorge Sousa

John Peter Karidis

Thomas Anthony Cofino

Arnold Halperin

John D Mackay

Huntington W Curtis

Danny C Wong

Ka-Chiu Woo

Arthur E Falls

Shinwu Chiang

Xinyu Harry Zang

Kenneth Alan Goldman

Rene D Martinez

Kenneth Gilbert Roessler

James Christopher Mahlbacher

Anand Narasimhan

James Michael Hammond

Kuan-Hung Chen

Michael Servedio

Gary E O'Neil

Paul J Sousa

Shaul Halevi

Rene Dominic Martinez

Gary E O'neil

Trieu Chan Chieu

A low friction horizontal probing fixture includes two rails of a base unit and two slide units respectively disposed on and being slidable along the rails. Each slide unit has a slide seat that is disposed adjacent to a respective one of the rails, rolling members that are connected to the slide seat and that are rollable on the respective rail so that the slide seat is movable along the respective rail, and a lock mechanism that is disposed on the slide seat and that is operable to position the slide seat relative to the respective rail. A guiding member is connected co-movably to the slide units.

Low friction horizontal probing fixture

A method and an apparatus for evaluating an expression embedded inside a communication packet received from an RFID (Radio Frequency Identification) interrogator device are described. The evaluation result may determine a selection with another RFID interrogator device. An RFID data packet may be sent to an RFID interrogator device based on a selection to be associated with the RFID interrogator. A task may be performed based on the evaluation as instructed by a remote RFID interrogator through a command included in the wireless communication packet.

Method and apparatus for active RFID network

The system of the present invention includes a large-zone RFID reader, a plurality of small-zone RFID readers, and a plurality of RFID tags. The large-zone RFID reader covers areas which are not covered by the small-zone RFID readers. The output power of the small-zone RFID readers is controlled by the large-zone RFID reader based on RFID tag operation patterns of the small-zone RFID readers. The system reliability is improved by a method that uses reliable RFID tags, RFID reader beacon signals, and RFID tag's repetitive transmitting signals to detect tag failures. The system security is provided by a method that uses integrated crypto engines in both the RFID tags and RFID readers.

Method and system of using active RFID tags to provide a reliable and secure RFID system

An RF/ID interrogator is provided for recovering a data signal from an RF/ID tag. The interrogator includes a radio having a receiver portion to receive in-phase (I) and quadrature-phase (Q) signals from the RF/ID transponder transmitted at a predetermined bit-rate, and a processor coupled to the radio for controlling operation of the radio in accordance with stored program instructions. In one embodiment, the interrogator performs over-sampling of the data signal received from the RF/ID tag in order to provide a high data recovery rate. The processor controls the over-sampling of the I and Q signals at a sampling rate higher than the transmitted bit-rate of the I and Q signals to provide plural signal samples that are stored in a buffer memory. The processor compares the relative polarity of successive ones of the plural signal samples. Based on this comparison, data bits are derived from the successive ones of the plural signal samples in correspondence with the number of the successive ones of the plural signal samples having same relative polarity. In another embodiment, the interrogator performs a selection between the I and Q signals in order to achieve optimum data recovery. The processor detects relative signal strength of the I and Q signals, and selects one of the I and Q signals for subsequent processing based on the detected relative signal strength. Data bits are then recovered from the selected one of the I and Q signals.

Data recovery system for radio frequency identification interrogator

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.

Apparatus for transporting radio frequency power to energize radio frequency identification transponders

An apparatus, a system, and a method for communication between multiple base stations and radio frequency (RF) transponders (RF Tags) is disclosed. A first radio frequency (RF) base station for communicating RF signals with an RF tag communicates external trigger signals with at least a second RF base station, which causes the second RF base station to begin transmission.

Apparatus, system, and method for communication between multiple base stations and radio frequency (RF) tags

An RF/ID interrogator recovers a backscattered data signal from a moving RF/ID transponder by combining the received in-phase (I) and quadrature-phase (Q) components of the signal in a manner that cancels out the amplitude nulls and phase reversals caused by movement of the RF/ID transponder. More particularly, the RF/ID interrogator comprises a radio having a transmitter portion to provide an RF carrier signal and a receiver portion to receive the I and Q signals from the RF transponder. A bandpass filter is coupled to the radio to remove direct current (DC) components from the I and Q. A processor coupled to the radio and the filter executes stored instructions to combine the filtered I and Q signals and recover the original backscattered data signal therefrom. In an embodiment of the invention, the processor estimates a phase angle .beta.(t) between the I and Q signals and the RF carrier by calculating an arctangent of a ratio of the filtered Q and I signals. Thereafter, the processor recovers the backscattered data signal by summing a product of the filtered I signal and the cosine of the estimated phase angle .beta.(t) with a product of the filtered Q signal and the sine of the estimated phase angle .beta.(t).

Radio frequency identification interrogator signal processing system for

A method of selecting groups of radio frequency RF transponders (tags) for communication between a base station and the tags. The tags are selected into groups according to a physical attribute of the signal sent by the tags to the base station, or according to the physical response of the tags to a physical attribute of the signal sent from the base station to the tags. Communication with the tags is thereby simplified, and the time taken to communicate with the first tag is markedly reduced.

Method for communicating with RF transponders

An apparatus and a method of transporting energy from a base station to energize a remote RF transponder having an energy store is described, comprising transporting power in pulses of frequencies chosen from a randomly ordered list of frequencies, wherein the time between pulses when little power is transmitted is less than the time taken for the remote transponder to deplete the energy store.

Method of transporting radio frequency power to energize radio frequency

A method of selecting groups of radio frequency RF transponders (tags) for communication between a base station and the tags. The tags are selected into groups according to a physical attribute ofthe signal sent by the tags to the base station, or according to the physical response of the tags to a physical attribute of the signal sent from the base station to the tags. Communication with the tags is thereby simplified, and the time taken to communicate with the first tag is markedly reduced.

Method of grouping RF transponders

A digital and analog controller for controlling a high-speed probe actuator is disclosed. This method and system provide the probe actuator system with improved damping ratio and reduced impact force, so the throughput of the tester is increased with fast settling actuator armature. With this method and system, the steady-state probe force is less sensitive to the servo system, test probe and variation in the probing distance d. An electronic circuit, which consists of analog operational amplifiers, monostable multivibrators, and D flip-flops, is presented for low-cost applications.

Method and system for controlling high-speed probe actuators

Apparatus and method are disclosed for performing testing and fault isolation of high density passive boards and substrates. Using a small number of moving probes, simultaneous network resistance and network capacitance measurements may be performed. Thus, test time is minimized by eliminating the need for electrical switching and/or excessive probe movement during the test of a normal circuit board network. Simultaneous network capacitance and network leakage measurement are also achieved using phase-sensitive detection. Dual-frequency measurement techniques allow the measurement of both the capacitance value and resistance value of a leakage path between a network being measured and an unknown network. Any leakage resistance between a network under test and ground or power planes within the circuit board may also be determined from the measurements. Simultaneous independent net-to-plane capacitance characterization is also achieved using signals of mutually independent frequencies accompanied by minimal signal processing. Thus, improved defect detection capabilities are obtained.

System and method for testing and fault isolation of high density

A method and apparatus for determining when transient responses of a signal have ended. A plurality of filters is provided. Operation of success of filters is cause to begin at successive times. The convergence of the outputs of the various filters is then tested. When convergence is detected, the signal provided by the first started filter of the successive filters that indicated convergence is used as an output signal. The signal is typically an electronic module test signal from an electronic module. Testing for convergence is performed by averaging outputs of each filter started to determine an average value; determining a deviation of each output of the filters from the average value; totaling the deviation to determine a total deviation; and comparing the total deviation to a reference level. Preferably, the total deviation is integrated over a period of time to provide an integrated total deviation; and the integrated total derivation is compared to the reference level.

Filtering for electronic module test

Direct communication between a primary portable unit initiating the communication and a secondary portable unit is established utilizing two handshaking operations. The first handshaking operation is performed in the base station channel to establish initial contact between the primary and secondary portable units. After initial contact is made, the second handshaking operation is performed to establish communication in an unoccupied channel. The base station channel and the unoccupied channel may be a TDMA/TDD channel or a TDMA/FDD channel.

Method and apparatus for direct communication in a TDMA radio

Apparatus and method are disclosed for performing testing and fault isolation of high density passive boards (e.g. unpopulated circuit boards) and substrates. Using a small number of moving probes, simultaneous network resistance and network capacitance measurements may be performed. Thus, test time is minimized by eliminating the need for electrical switching and/or excessive probe movement during the test of a normal circuit board network. Simultaneous network capacitance and network leakage measurement are also achieved using phase-sensitive detection. Dual-frequency measurement techniques allow the measurement of both the capacitance value and resistance value of a leakage path between a network being measured and an unknown network. Any leakage resistance between a network under test and ground or power planes within the circuit board may also be determined from the measurements. Simultaneous independent net-to-plane capacitance characterization is also achieved using signals of mutually independent frequencies accompanied by minimal signal processing. Thus, improved defect detection capabilities are obtained.

Growing community of inventors

Los Gatos, CA, United States of America

Li-Cheng Richard Zai