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Improved Dynamic Range ADCs
Navy SBIR 2009.2 - Topic N092-154 ONR - Mrs. Tracy Frost - [email protected] Opens: May 18, 2009 - Closes: June 17, 2009 N092-154 TITLE: Improved Dynamic Range ADCs TECHNOLOGY AREAS: Information Systems, Sensors, Electronics, Battlespace ACQUISITION PROGRAM: SSEE shipboard cryptographic suite OBJECTIVE: Devise innovative ways of producing sensitive, wideband low pass analog to digital converters that potentially deliver 500 MHz of instantaneous bandwidth with 12 significant bits. The digital data from this ADC should be capable of being decimated such that the resulting dynamic range has 16 effective bits over 10 MHz bandwidth. Such an ADC is needed by a wide range of military RF systems. DESCRIPTION: As part of the movement toward software defined radios, there is increasing interest in wideband digital reception using analog to digital converters (ADC) capable of digitally trading the bandwidth of the information band output for improved signal resolution within the remaining band. This allows one analog front end and ADC to service many simultaneous signals which may differ in their waveform and eases dynamic bandwidth allocation. Both these lower costs in dense signal environments. There is also a continuing need for improved dynamic range ADC since signal density is increasing in most bands, signal overlaying is increasingly common, and the total signal input to wideband systems will necessarily include all the signals present. All these factors increase the requirements for more dynamic range at every instantaneous bandwidth. PHASE I: Develop a new ADC circuit design concept to the point where performance simulations become feasible and realistic. Issues of thermal noise and clock jitter limits must be considered. PHASE II: Realize the design created in phase 1, measure its performance, and with that information, iterate the design at least once. Test the achieved behavior with both single and multiple tones at several output bandwidths. Demonstrate digitally controlled bandwidth/resolution trading. PHASE III: Demonstrate the ADC in a full receive chain relevant to EW, radar, or SIGINT applications and transition into US military systems. PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: Analog to digital converters are at the heart of all RF receivers and the specified performance goals are about 10 dB beyond the "Walden curve" state of the art values at both output band-widths. Thus the requested ADC could be applied in a wide range of systems. The largest commercial application is likely to be the wireless industry, especially for base stations. The larger dynamic range should enable more simultaneous signals to share a given band before each can no longer be resolved due to inaccuracies in the total signal representation. In addition, signals from public safety emergency such as building collapses should be receivable at lower signal amplitude, e.g. from further away or having been produced by weak batteries, because they will not be swamped by the normal environmental load of stronger signals. REFERENCES: 2. http://cat.inist.fr/?aModele=afficheN&cpsidt=15294698 3. http://focus.ti.com/lit/ds/symlink/ads5463-sp.pdf 4. http://wwwsscd.ee.sophia.ac.jp/Publication/0108mvl.pdf 5. http://findarticles.com/p/articles/mi_m0EIN/is_/ai_n26744687 KEYWORDS: Analog to digital converters, sigma-delta ADC, flash ADC, optical ADC, dynamic component matching, signal to noise ratio
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