Coded data generation or conversion – Converter compensation
Patent
1998-06-17
2000-08-01
Young, Brian
Coded data generation or conversion
Converter compensation
H03M 166
Patent
active
060973242
ABSTRACT:
An A/D system provides an expanded SFDR when compared to the SFDR of individual A/D(s) that make up the A/D system. In response to an analog input signal whose amplitude would result in an narrower SFDR for a first A/D, the A/D system uses an amplitude adjuster which receives the analog input signal and produces an amplitude-limited signal with resulting signal distortion to the first A/D. By amplitude-limiting the analog input signal, the A/D system produces the resulting signal distortion but reduces or "clips" the amplitude of the analog input signal, thereby improving the SFDR performance of the first A/D by reducing the spurious distortion produced by the first A/D. The signal distortion resulting from the amplitude adjustment is routed to a second A/D. The first A/D converts the amplitude-limited analog signal to a digital signal with an expanded SFDR due to the lower amplitude of the adjusted analog signal. The second A/D receives the portion of the analog input signal removed by clipping which can be referred to as the signal distortion. The second A/D converts the signal distortion, which typically has a lower amplitude than the adjusted analog signal, to a digital signal with at least an acceptable SFDR. The A/D system combines the resulting digital signals from the first and second A/Ds to produce the desired converted digital signal with an extended SFDR. The SFDR is extended because the relative difference is increased between the amplitudes of the digital output signal and the spurious distortion when compared to the amplitudes of the digital output signal and the spurious distortion if the analog input signal had been converted by the first A/D without amplitude adjustment.
REFERENCES:
patent: 4408352 (1983-10-01), Dudding
patent: 4580105 (1986-04-01), Myer
patent: 4583049 (1986-04-01), Powell
patent: 4665560 (1987-05-01), Lange
patent: 4885551 (1989-12-01), Myer
patent: 4926136 (1990-05-01), Olver
patent: 5012490 (1991-04-01), Myer
patent: 5304945 (1994-04-01), Myer
patent: 5430893 (1995-07-01), Myer
patent: 5619168 (1997-04-01), Myer
patent: 5798724 (1998-08-01), Myers
patent: 5847603 (1998-12-01), Myer
"Expanding Bit Resolution Of An A to D Converter, Dec. 1967." IBM Technical Disclosure Bulletin, vol. 10, No. 7, pp. 919-920, XP002116707, New York, US.
Patent Abstracts of Japan, vol. 015, No. 269 (E1087), Jul. 9, 1991 (1991-07-09) & JP03089627A (Teac Corp), Apr. 15, 1991 (1991-04-15).
Seifert, E. et al.: "Enhancing The Dynamic Range of Analog-To-Digital Converters By Reducing Excess Noise," proceedings of the Pacific Rim Conference on Communications, Computers & Signal Processing, Victoria, Jun. 1-2, 1989, Jun. 1, 1989 (1989-06-01), pp. 574-576, Institute of Electrical & Electronics Engineers.
Myer Robert Evan
Patel Mohan
Wen Jack Chi-Chieh
Lucent Technologies - Inc.
Young Brian
LandOfFree
Method and apparatus for extending the spurious free dynamic ran does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for extending the spurious free dynamic ran, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for extending the spurious free dynamic ran will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-668245