Ransom W Stephens

US Patent:

7191080, Mar 13, 2007

Filed:

Apr 12, 2005

Appl. No.:

11/104124

Inventors:

Ransom W. Stephens - Petaluma CA, US

Assignee:

Agilent Technologies, Inc. - Santa Clara CA

International Classification:

G01R 27/00

US Classification:

702 69, 702181

Abstract:

A random component of jitter and a deterministic component of jitter are separated. A measured jitter distribution is obtained. A form is selected for a selected component of jitter. The selected component of jitter is either the random component of jitter or the deterministic component of jitter. A remaining component of jitter is either the random component of jitter or the deterministic component of jitter, whichever is not the selected component of jitter. The selected form for the selected component of jitter is convolved with a generalized function for the remaining component of jitter to produce a resulting equation. The resulting equation is fitted to the measured jitter distribution.

US Patent:

20020049049, Apr 25, 2002

Filed:

Sep 21, 2001

Appl. No.:

09/957855

Inventors:

Joel Sandahl - Southlake TX, US
Ransom Stephens - Mansfield TX, US
Thomas Mezger - Southlake TX, US

International Classification:

H04M011/10
H04M003/42

US Classification:

455/414000, 455/412000

Abstract:

A system for delivering information services is provided having a service provider capable of sending directory messages and information service messages to wireless messaging devices through one or more regional transmission systems. The directory messages define a directory of information service which may be organized in categories and subcategories. In response to receiving directory messages, each messaging device builds or updates a directory profile in its memory. The service provider sends information service messages to messaging devices for information services under the directory. The directory and information services messages are sent on the same radio signaling address, and each messaging device is programmed to receive directory and information service messages on that radio signaling address. The user of each messaging device can enable or disable different information services at the device without interaction with the service provider. Information service messages when received for information services enabled by the user of each messaging device are stored in memory of the device for retrieval by the user on the device's display. Information service messages may be sent in different geographic regions in which the user of each messaging device may further enable or disable reception of information service messages at the device based on the device's home region and/or roam (non-home region) reception. Advertising may be included with stored information service messages when retrieved by the user. Further, the user of each messaging device may manually enter information services independent of directory messages in the stored directory profile of the device to enable reception of such information services at the device.

US Patent:

20060229835, Oct 12, 2006

Filed:

Mar 29, 2005

Appl. No.:

11/092091

Inventors:

Ransom Stephens - Petaluma CA, US

International Classification:

G01R 29/26

US Classification:

702069000

Abstract:

Random and deterministic components of jitter are separated. A measured value for deterministic jitter and a plurality of values for random jitter are used to calculate a plurality of first ratios (ξ) of random jitter to deterministic jitter. For each of the plurality of values for random jitter, the value for random jitter is convolved with the measured value for deterministic jitter and a double delta approximation is performed on the result to calculate a plurality of second ratios (ξ) of random jitter to deterministic jitter. A double delta approximation is performed on a measured jitter distribution to obtain a ratio (ξ) of random jitter to deterministic jitter. The ratio (ξ) is adjusted using a relationship of the plurality of first ratios (ξ) to the plurality of second ratios (ξ) in order to produce a corrected ratio (ξ).

US Patent:

20110235694, Sep 29, 2011

Filed:

Dec 20, 2010

Appl. No.:

12/973709

Inventors:

Ransom W. Stephens - Petaluma CA, US
Muralidharan Karapattu - Bangalore, IN
Sampathkumar R. Desai - Bangalore, IN
John C. Calvin - Portland OR, US

Assignee:

Tektronix, Inc. - Beaverton OR

International Classification:

H04B 17/00

US Classification:

375226

Abstract:

A signal generating device has a display and a central processing unit for setting parameters for a serial data pattern and parameters for deterministic and random jitter impairments, and a displacement crest factor emulation impairment to be applied to the serial data pattern. A waveform record file is generated using the serial data pattern parameters, the impairment parameters for the deterministic jitter and random jitter, and the displacement crest factor emulation impairment. The displacement crest factor emulation impairment is selectively positioned in the impaired serial data pattern. A waveform generation circuit receives the waveform record file and generates an impaired serial data pattern analog output signal based on the serial data pattern, deterministic and random jitter impairments, and the displacement crest factor emulation impairment with the displacement crest factor emulation impairment being selectively positioned in the impaired serial data pattern analog output signal.