Company Filing History:
3 out of 763 
2 out of 3,430 
2 out of 2,644 
Years Active: 1997-2007
Title: The Innovations of Frederic M. Stubbe
Introduction
Frederic M. Stubbe is a notable inventor based in Irvine, California, recognized for his contributions to digital communication technologies. With a total of eight patents to his name, Stubbe has made significant advancements in the field of digital subscriber line (DSL) communication systems.
Latest Patents
One of his latest patents is focused on modulation switching for DSL signal transmission. This innovation allows a DSL communication system to utilize the high-frequency band of a standard telephone line without requiring a plain old telephone service (POTS) splitter in the resident's home. The system employs constant envelope modulation or quadrature amplitude modulation to optimize DSL signals. When a telephone is detected as off-hook, constant envelope modulation is used to reduce intermodulation product distortion, thereby minimizing audible noise for the user. Conversely, when the telephone is on-hook, QAM is utilized to maximize upstream data rates, as any noise generated is not an issue due to the non-use of the POTS frequency band.
Another significant patent involves a system and method for reducing or eliminating unwanted sidebands in signals derived from quadrature modulators. This innovation includes an unwanted sideband detector that identifies unwanted components in the output signal, allowing for corrections to be made to the baseband signal before it is input to the quadrature modulator.
Career Highlights
Frederic M. Stubbe has had a distinguished career, working with prominent companies such as Conexant Systems, Inc. and Rockwell International Corporation. His work in these organizations has contributed to the development of advanced communication technologies.
Collaborations
Throughout his career, Stubbe has collaborated with notable individuals, including Kenneth David Ko and David O. Anderton. These partnerships have further enhanced his innovative contributions to the field.
Conclusion
Frederic M. Stubbe's work in DSL communication systems and modulation techniques has significantly impacted the industry. His eight patents reflect his dedication to innovation and his ability to solve complex problems in digital communication.