Patents by Inventor Feng Ren

Feng Ren has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7309157
    Abstract: A circuit for temperature sensing provides a bias current to a PN junction, and the PN junction provides a PN junction voltage in response to the bias current. Also, a parasitic resistance may be coupled in series with the PN junction. The circuit for temperature sensing is configured to determine the temperature of the PN junction based on the PN junction voltage. Further, the circuit includes registers which store ?trim, which is based on the difference between the non-ideality of the PN junction used from a reference PN junction; ?I, which is based on the difference between a reference bias current and the bias current for the part; Rtrim, which is based the parasitic resistance; and Ntrim, which includes other offsets. The registers may be set during trimming and/or calibration to provide accurate temperature sensing for the parameters employed.
    Type: Grant
    Filed: September 28, 2004
    Date of Patent: December 18, 2007
    Assignee: National Semiconductor Corporation
    Inventors: Mehmet Aslan, Chungwai Benedict Ng, Eric Tam, Qing Feng Ren, Dan D'Aquino
  • Patent number: 7298802
    Abstract: The invention discloses a signal-to-interference ratio (SIR) measurement method. The method measures interference power (I) of a single-path signal after the received signal is demodulated by the single-path demodulators of multipath receiving device at the receiving end. The total interference power is obtained by equipartition combining with the measured interference power of each single-path signal. The signal power (S) is obtained by measuring after maximum ratio combination of each single-path signal. The SIR of the received signal is the division of the signal power and the total interference power. An apparatus, implementing mentioned method, sets the interference power measurement-device in the RAKE combiner and the signal power measurement-device after the RAKE combiner. In this way, the interference measurement can effectively provide more information and can more really response to the channel variation.
    Type: Grant
    Filed: February 19, 2003
    Date of Patent: November 20, 2007
    Assignee: Huawei Technologies Co., Ltd.
    Inventors: Feng Ren, Zhibin Zheng, Yuehua Chen
  • Publication number: 20070174025
    Abstract: A method for simulating a hydroforming process includes modeling a virtual hydroforming die and a virtual tubular workpiece. The virtual workpiece is placed within the die after the die has been expanded. The die is then contracted to a finished size while the workpiece is deformed into a non-circular cross section in contact with the virtual die. The workpiece is subsequently pressurized to simulate production of a finished part.
    Type: Application
    Filed: January 26, 2006
    Publication date: July 26, 2007
    Applicant: FORD GLOBAL TECHNOLOGIES, LLC
    Inventors: Feng Ren, Zhiyong Xia, Dan Zeng
  • Publication number: 20070173964
    Abstract: A method for determining compensated addendum and binder surfaces as part of a springback compensated stamping die for producing a stamped part includes modeling of the existing addendum surface and binder surface of the stamping die. The addendum and binder surfaces are modified according to a number of compensatory surface displacements and in-plane rotations required for springback compensation of the finished stamped part. Following this modification, the stamped part may be separated from the addendum and binder without a loss of dimensional accuracy.
    Type: Application
    Filed: January 26, 2006
    Publication date: July 26, 2007
    Applicant: FORD GLOBAL TECHNOLOGIES, LLC
    Inventors: Feng Ren, Zhiyong Xia
  • Patent number: 7157068
    Abstract: The present invention describes the preparation of carbon nanotubes of varied morphology, catalyst materials for their synthesis. The present invention also describes reactor apparatus and methods of optimizing and controlling process parameters for the manufacture carbon nanotubes with pre-determined morphologies in relatively high purity and in high yields. In particular, the present invention provides methods for the preparation of non-aligned carbon nanotubes with controllable morphologies, catalyst materials and methods for their manufacture.
    Type: Grant
    Filed: May 20, 2002
    Date of Patent: January 2, 2007
    Assignee: The Trustees of Boston College
    Inventors: Wenzhi Li, Jian Guo Wen, Zhi Feng Ren
  • Patent number: 7117065
    Abstract: A method for modifying a stamping die to compensate for springback includes the steps of stamping a first part using a base, or pre-existing die set, and creating a surrogate die having the shape of the first stamped part. These steps are followed by simulated stamping of a blank with the surrogate die, where the blank is shaped according to the desired finished part. Then, the base die is modified by mapping the forming stresses, from the stamped blank, to an indicator blank, which is allowed to relax and then is employed as a template for modification of the base die. Following this, the accuracy of the newly modified base die is determined by stamping a second part in the modified base die and by comparing a number of dimensions of the second part with a number of corresponding dimensions of the desired finished part.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: October 3, 2006
    Assignee: Ford Global Technologies, LLC
    Inventors: Zhiyong Cedric Xia, Feng Ren
  • Patent number: 7082377
    Abstract: A temperature measurement circuit for a dual junction temperature sensor is provided. The temperature measurement circuit is configured to provide separate bias currents to the junctions in the temperature sensor. The temperature measurement circuit includes two signal channels configured to provide an intermediate differential signal from a differential input signal that is received from the temperature sensor. Also, the temperature measurement circuit may include one or more multiplexer circuits that are configured to control the intermediate differential signal. The temperature sensor circuit further includes a control circuit configured to adjust the bias currents and to control the multiplexer circuits such that several different differential voltages can be provided by the signal channels.
    Type: Grant
    Filed: March 3, 2004
    Date of Patent: July 25, 2006
    Assignee: National Semiconductor Corporation
    Inventors: Mehmet Aslan, Qing Feng Ren, Richard Henderson
  • Patent number: 6947809
    Abstract: A method of developing a stamping die for a workpiece is provided, which includes the steps of stamping a workpiece in a current die. A measurement is made of the stamped workpiece to determine its profile. The profile is compared with the design intent workpiece to determine dimensional variance. If the variance is within predetermined limits, the development is complete. If the variance is beyond limits, a conceptual determination is made of the residual forces in the current die stamped workpiece when the current die stamped workpiece is restamped by a design intent die. This conceptual determination is carried out on a computer. From the determination of residual forces, a new current die is developed. The new current die then stamps the workpiece. The steps are repeated until the stamped workpiece profile is within predetermined limits.
    Type: Grant
    Filed: March 5, 2003
    Date of Patent: September 20, 2005
    Assignee: Ford Global Technologies
    Inventors: Feng Ren, Zhiyong Cedric Xia
  • Patent number: 6808307
    Abstract: A method and apparatus improves the accuracy of temperature measurements by sampling measurements from a remote sensor, where currents of different current densities are applied to the remote sensor in a time-interleaved fashion. The remote sensor includes at least one PN junction that produces a voltage corresponding to the applied current at each instance of time, and related to the temperature of the remote sensor. By applying time-interleaved current densities to the remote sensor, adverse effects from temperature variations during the measurement are minimized. Sequences of current biases having differing current densities in a forward order are applied to the remote sensor, followed by the same sequence being applied to the remote sensor in a reverse order. Similarly, a random or pseudo-random sequence may be employed in a forward and reverse order. The application of forward and reverse sequences is utilized to minimize errors in the temperature measurement.
    Type: Grant
    Filed: January 16, 2002
    Date of Patent: October 26, 2004
    Assignee: National Semiconductor Corporation
    Inventors: Mehmet Aslan, Richard Dean Henderson, Michael Wong, Qing Feng Ren, Chungwai Benedict Ng, Hideya Oshima
  • Publication number: 20040176863
    Abstract: A method of developing a stamping die for a workpiece is provided, which includes the steps of stamping a workpiece in a current die. A measurement is made of the stamped workpiece to determine its profile. The profile is compared with the design intent workpiece to determine dimensional variance. If the variance is within predetermined limits, the development is complete. If the variance is beyond limits, a conceptual determination is made of the residual forces in the current die stamped workpiece when the current die stamped workpiece is restamped by a design intent die. This conceptual determination is carried out on a computer. From the determination of residual forces, a new current die is developed. The new current die then stamps the workpiece. The steps are repeated until the stamped workpiece profile is within predetermined limits.
    Type: Application
    Filed: March 5, 2003
    Publication date: September 9, 2004
    Applicant: FORD GLOBAL TECHNOLOGIES, LLC
    Inventors: FENG REN, ZHIYONG CEDRIC XIA
  • Patent number: 6774676
    Abstract: The present invention is directed to a buffer having dual thresholds. The buffer has an input terminal and an output terminal and comprises a current source, first through fourth transistors, a current mirror, and an output driver. The buffer uses an “analog” topology to achieve accurate buffering when the thresholds of applied signals are not centered about the mid-supply range. The buffer is useful (among other circuits) in analog and mixed circuit integrated circuits that have relatively high voltage supply levels and signals having logic thresholds that are not centered about the mid-supply level. The buffer uses feedback from the output to achieve hysteresis.
    Type: Grant
    Filed: February 24, 2003
    Date of Patent: August 10, 2004
    Assignee: National Semiconductor Corporation
    Inventors: Mehmet Aslan, Qing Feng Ren
  • Publication number: 20030218999
    Abstract: The invention discloses a signal-to-interference ratio (SIR) measurement method. The method measures interference power (I) of a single-path signal after the received signal is demodulated by the single-path demodulators of multipath receiving device at the receiving end. The total interference power is obtained by equipartition combining with the measured interference power of each single-path signal. The signal power (S) is obtained by measuring after maximum ratio combination of each single-path signal. The SIR of the received signal is the division of the signal power and the total interference power. An apparatus, implementing mentioned method, sets the interference power measurement-device in the RAKE combiner and the signal power measurement-device after the RAKE combiner. In this way, the interference measurement can effectively provide more information and can more really response to the channel variation.
    Type: Application
    Filed: February 19, 2003
    Publication date: November 27, 2003
    Applicant: Huawei Technologies Co., Ltd.
    Inventors: Feng Ren, Zhibin Zheng, Yuehua Chen
  • Publication number: 20030004058
    Abstract: The present invention describes the preparation of carbon nanotubes of varied morphology, catalyst materials for their synthesis. The present invention also describes reactor apparatus and methods of optimizing and controlling process parameters for the manufacture carbon nanotubes with pre-determined morphologies in relatively high purity and in high yields. In particular, the present invention provides methods for the preparation of non-aligned carbon nanotubes with controllable morphologies, catalyst materials and methods for their manufacture.
    Type: Application
    Filed: May 20, 2002
    Publication date: January 2, 2003
    Applicant: Trustees of Boston College
    Inventors: Wenzhi Li, Jian Guo Wen, Zhi Feng Ren
  • Patent number: 5982336
    Abstract: The present invention discloses an integrated dipole antenna and down converter apparatus. The integrated dipole antenna and down converter apparatus includes a dipole antenna for receiving microwave signals therein. The integrated dipole antenna and down converter apparatus further includes a down converter for receiving processed signals of the microwave signals from the dipole antenna for converting the processed signals to signals of lower frequency. The down converter includes main plate for supporting a tunable notch mechanical. The down converter further includes a tunable dual band mechanical filter supported on the plate. The dual band mechanical filter and notch mechanical filter both include capacitance adjusting means adjustable by applying a mechanical screwing method whereby signal filtering efficiency is improved by reducing signal dissipation and the performance of the down converter is improved with the mechanically adjustable dual band and notch mechanical filters.
    Type: Grant
    Filed: August 1, 1998
    Date of Patent: November 9, 1999
    Assignee: Transystems, Inc.
    Inventors: Charles Wen, Feng-Ren Wang, Shun-Yu Chien
  • Patent number: 4737497
    Abstract: Disclosed are novel bis-dioxopiperazine derivatives, process for their preparation, antitumor agents comprising them and compositions containing them.The bis-dioxopiperazine derivatives are represented by the following general formula (I): ##STR1## wherein R.sub.1 represents a hydrogen atom or a lower alkyl group having 1 to 4 carbon atoms; R.sub.2 represents a hydrogen atom or a group of ##STR2## R.sub.3 and R.sub.4, which are respectively independent and are the same or different, represent respectively a lower alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 7 carbon atoms or a heterocyclic radical selected from the group consisting of substituted or unsubstituted piperidino, substituted or unsubstituted piperazino, substituted or unsubstituted morpholino and substituted or unsubstituted thiomorpholino, or R.sub.3 and R.sub.
    Type: Grant
    Filed: April 4, 1984
    Date of Patent: April 12, 1988
    Assignee: Zenyaki Kogyo Kabushiki Kaisha
    Inventor: Yun-feng Ren