James C Liu

US Patent:

6798310, Sep 28, 2004

Filed:

Jan 7, 2003

Appl. No.:

10/337748

Inventors:

Kenneth H. Wong - Santa Rosa CA
James C. Liu - Santa Rosa CA
James E. Tranchina - Forestville CA

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

H01P 126

US Classification:

333 24C, 333 12

Abstract:

A DC-block includes a capacitor incorporated into a conductor, such as a center conductor of a coaxial structure. The DC block provides low insertion loss at high frequencies, and a low cutoff frequency. The small physical size and high capacitance of the DC block provides for a high self-resonant frequency and ultra-broadband performance.

US Patent:

6914436, Jul 5, 2005

Filed:

Jan 30, 2003

Appl. No.:

10/355961

Inventors:

James C. Liu - Santa Rosa CA, US
Robert L. Shimon - Santa Rosa CA, US
Shigetsune Torin - Santa Rosa CA, US
Kenneth H. Wong - Santa Rosa CA, US

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

G01R035/00
G01D018/00

US Classification:

324601, 702 85

Abstract:

An electronic calibration circuit for calibrating a network analyzer. The electronic calibration circuit comprises at least one port for coupling the electronic calibration circuit to the network analyzer. A plurality of switching circuits coupled to the port are operable to provide a plurality of impedance states for electronically calibrating the network analyzer, wherein a transmission line couples at least two of the plurality of switching circuits, the transmission line short enough to reduce interactions of impedance mismatches and to reduce transmission loss. The port and the plurality of switching circuits are comprised within an integrated circuit having a package size small enough to avoid cavity resonance at a high frequency.

US Patent:

6965241, Nov 15, 2005

Filed:

Oct 7, 2003

Appl. No.:

10/680329

Inventors:

James C. Liu - Santa Rosa CA, US
Kenneth H. Wong - Santa Rosa CA, US
Robert L. Shimon - Santa Rosa CA, US
Paul E. Cassanego - Santa Rosa CA, US
Srinivas M. Sundaram - Santa Rosa CA, US
Shigetsune Torin - Santa Rosa CA, US
Richard R. Hawkins - Santa Rosa CA, US

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

G01R035/00

US Classification:

324601, 324 7623, 324638

Abstract:

Testing is performed on a device under test. A first port of a first calibration module is connected to the device under test. A second port of the first calibration module is connected to a network analyzer. A first port of a second calibration module is connected to the device under test. A second port of the second calibration module is connected to the network analyzer. A measurement calibration and testing are performed without disconnecting the first port and the second port of the first calibration module and without disconnecting the first port and the second port of the second calibration module.

US Patent:

6995571, Feb 7, 2006

Filed:

Jan 3, 2005

Appl. No.:

11/028161

Inventors:

James C. Liu - Santa Rosa CA, US
Kenneth H. Wong - Santa Rosa CA, US
David V. Blackham - Santa Rosa CA, US

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

G01R 35/00

US Classification:

324601, 324 7622

Abstract:

In one embodiment, a method comprises applying a stimulus signal to a reference frequency translation device (FTD) by a vector network analyzer during a calibration mode, wherein the reference FTD possesses equal conversion efficiency in forward and reverse directions and the reference FTD possesses unknown input and output reflection characteristics; measuring a response of the reference FTD; and determining forward and reverse transmission tracking error terms using data from the measured response and single-port error calibration terms.

US Patent:

7013229, Mar 14, 2006

Filed:

Nov 13, 2003

Appl. No.:

10/712645

Inventors:

Kenneth H. Wong - Santa Rosa CA, US
James C. Liu - Santa Rosa CA, US
Johan J. Ericsson - Windsor CA, US

Assignee:

Agilent Technologies, Inc. - Palo Alto CA

International Classification:

G01R 35/00

US Classification:

702107, 702 85

Abstract:

Calibration is performed for the testing of a device under test. A first port of the device under test is connected to a port of a calibration module. A second port of the device under test is connected to a first port of a device tester. A third port of the device under test is connected to a second port of a device tester. The device tester performs measurements by the device tester to obtain calibration parameters. In response to commands from the device tester, the calibration module changes termination values at the port of the calibration module. The changing of the termination values is performed without physical disconnection of the port of the calibration module from the first port of the device under test.

US Patent:

7124049, Oct 17, 2006

Filed:

Jan 3, 2005

Appl. No.:

11/028159

Inventors:

Kenneth H. Wong - Santa Rosa CA, US
David V. Blackham - Santa Rosa CA, US
James C. Liu - Santa Rosa CA, US
Keith F. Anderson - Santa Rosa CA, US

Assignee:

Agilent Technologies, Inc. - Santa Clara CA

International Classification:

G06F 19/00

US Classification:

702107

Abstract:

In one embodiment, a method comprises storing parameters that are related to switch error correction terms of a vector network analyzer (VNA), and applying a calibration process of a TRL group of calibration processes to the VNA to generate calibration measurements, wherein the calibration process generates calibration measurements, calculates a switch error correction matrix using the stored parameters and a subset of the calibration measurements, and applies the switch error correction matrix to calibration measurements before solving for eight-systematic error terms associated with the calibration process.

US Patent:

7652484, Jan 26, 2010

Filed:

Feb 22, 2007

Appl. No.:

11/677710

Inventors:

Kenneth H. Wong - Santa Rosa CA, US
James C. Liu - Santa Rosa CA, US
Keith F. Anderson - Santa Rosa CA, US
Bobby Y. Wong - Stockton CA, US

Assignee:

Agilent Technologies, Inc. - Santa Clara CA

International Classification:

G01R 35/00
G01D 18/00

US Classification:

324601, 324638, 324642, 702 85

Abstract:

In one method of calibrating an instrument having N ports, where N>=2, cables of a first type are characterized by connecting a first cable between two of the ports; performing an “unknown-thru” full two-port calibration between the two ports; obtaining a S-parameter of the first cable; saving the S-parameter of the first cable; and then repeating the connecting, performing, obtaining and saving for additional cables having the first type. The cables having the first type are then disconnected from one of the two ports and a measurement plane is transferred from the connected end of the cable to the disconnected end of the cable. Cables of a second type are then characterized by connecting a second cable between the second of the two ports and the disconnected end of the first cable; measuring a S-parameter of the second cable; and saving the S-parameter of the second cable.

US Patent:

20060084426, Apr 20, 2006

Filed:

Oct 18, 2004

Appl. No.:

10/967877

Inventors:

Keith Anderson - Santa Rosa CA, US
Richard Hawkins - Santa Rosa CA, US
James Liu - Santa Rosa CA, US
Kenneth Wong - Santa Rosa CA, US

International Classification:

H04Q 7/20

US Classification:

455423000, 455063100

Abstract:

A Vector Network Analyzer is equipped with receivers for measuring a, b, aand band which can each be tuned to track either the RF signal (F) applied to the FTD or to the IF (F) produced by the FTD. Additional forward side and reverse side mixers are provided and are driven by the auxiliary LO for the FTD. The additional mixers can be located in the RF/IF path, such that there is a sequential double conversion of the RF/IF: one by the auxiliary LO followed by another conversion of those results by the main LO. The additional mixers could also be located it the LO path, such that the main LO is first converted to an image involving the auxiliary LO, and the RF/IF is then subsequently converted using that image as an ‘artificial’ LO. During a forward direction measurement of an FTD, the applied RF signal (F) is converted to the IF with the additional forward side mixers that feeds the receivers for aand b. This references the forward measurements to Fand allows the FTD's input reflection and forward conversion magnitude and phase to be determined. A companion reverse direction measurement is to set the swept RF source to Fof the FTD's output. The additional reverse side mixers convert Fback to Fso that receivers for aand bare at the same frequency at the FTD's input port. This references the reverse measurements to F. The FTD's output reflection and reverse conversion magnitude and phase can be determined.