James A Wilkerson

US Patent:

20020061034, May 23, 2002

Filed:

Jun 29, 2001

Appl. No.:

09/897538

Inventors:

David Schneider - Melbourne FL, US
James Wilkerson - Satellite Beach FL, US
James Wernlund - Indialantic FL, US

Assignee:

JDS Uniphase Corporation - San Jose CA

International Classification:

G02F001/03

US Classification:

372/026000

Abstract:

A microcontroller-based controller executes interleaved DC bias and gain control routines using monitored values of the monitored photocurrent output signal of a Mach-Zehnder laser modulator to derive a gain setting for the modulation drive signal and a bias level setting for the DC bias level, without tuning or adjustment. Subsequent to convergence of the gain and bias level settings, the control unit may repetitively interrupt and restart the DC bias and gain control routine at intervals that are staggered in a random time fashion, to achieve spectral dispersion of the gain and bias level settings, and provide insensitivity to periodic environmental noise.

US Patent:

58126040, Sep 22, 1998

Filed:

Jul 16, 1996

Appl. No.:

8/680821

Inventors:

Charles A. Herbst - Palm Bay FL
Larry John Fruit - Melbourne FL
James Allan Wilkerson - Palm Harbor FL

Assignee:

Scientific-Atlanta, Inc. - Norcross GA

International Classification:

H04L 2720

US Classification:

375308

Abstract:

Constant envelope angle modulation apparatus comprises a frequency synthesizer for outputting a stepped output waveform having a selectable precise output frequency. The output of the synthesizer provides an input to a mixer for O-QPSK modulating a received information signal. The O-QPSK modulated signal is then hard-limited, for example, via a series of hard limiting amplifier and filter circuits and a divider circuit. Preferably, a data stream for modulation may be filtered via a filter having an approximately 70-100% roll-off characteristic, such as a root raised cosine filter. A hard-limited, constant envelope angle modulated signal results that is easily frequency converted to, for example, microwave frequencies for landline or satellite applications via a simple multiplier circuit. The multiplier circuit preferably comprises a series of stage-filtered multipliers and band pass filters to achieve the desired output microwave frequency.

US Patent:

54540097, Sep 26, 1995

Filed:

Jan 13, 1994

Appl. No.:

8/181318

Inventors:

Larry J. Fruit - Seminole FL
John A. Schachte - Indialantic FL
Charles A. Herbst - Palm Bay FL
James A. Wilkerson - Palm Harbor FL

Assignee:

Scientific-Atlanta, Inc. - Norcross GA

International Classification:

H04B 1713

US Classification:

375202

Abstract:

A satellite communications system for dispersing energy over a wide bandwidth includes a transmitter, a communication link, and a receiver. The transmitter takes a digital data signal and modulates that signal at a prescribed carrier frequency. The modulated digital data signal is then spread over M adjacent digital channels (M. gtoreq. 2 and being an integer multiple of 2), each channel containing the same information, to disperse the energy over a wide frequency range. The spectral bandwidth of the adjacent digital channels is chosen with compressed spacing to conserve bandwidth. Next, the spread modulated data signal is transmitted via the communication link to the receiver. In particular, a waveform generator at the transmitter generates a phase-aligned multichannel frequency diversity waveform according to a data clock at a predetermined phase relationship to the digital data. At the receiver, the spread modulated data signal received is mixed with a despreading waveform generated in a similar manner to the waveform spectrum generated at the transmitter to recover the modulated data signal. The despreading waveform is generated according to a symbol clock signal recovered from the received modulated data signal.

US Patent:

20200412442, Dec 31, 2020

Filed:

Mar 8, 2019

Appl. No.:

16/977029

Inventors:

- Tampa FL, US
James WILKERSON - Oldsmar FL, US
Shawn O'BRIEN - Saint Petersburg FL, US

International Classification:

H04B 7/185

Abstract:

A system for network agnostic satellite communications includes an antenna configured to receive at least one antenna receive beam including multiple receive carriers multiplexed in at least one of frequency or time. The system further includes a signal processor configured to receive the multiple receive carriers and to extract data from at least one receive carrier of the multiple receive carriers. The system further includes an input device configured to receive at least one desirable communication parameter. The system further includes a control processor designed to determine actual parameters corresponding to the multiple receive carriers of the at least one antenna receive beam. The control processor is further designed to select an optimal receive carrier by comparing the at least one desirable communication parameter to the actual parameters. The control processor is further designed to establish a current communication link with the optimal receive carrier.