SBIR-STTR Award

This Small Business Innovation Research Phase I project demonstrates a breakthrough approach to high-resolution linearity error compensation (LinComp) using computationally-efficient digital signal processing to reduce harmonic and intermodulation distortion in digital-to-analog converters (DACs), analog-to-digital converters (ADCs), sampling circuitry, and radio frequency amplifiers by at least 24 dB. This technology improves the dynamic range by at least four bits, enabling very accurate synthesis of data at high intermediate frequencies (IF) with very high sample rates (e.g., 18-bit dynamic range with 100 MHz sample rate or 12-bit dynamic range at GHz sample rates). The LinComp technology reduces the size, power, and cost of radar systems and RF transceivers by eliminating much of the RF electronics and reducing the digital signal processing requirements. The significant performance improvements afforded by this approach over traditional compensation techniques will be demonstrated in Phase I by developing a system which will achieve 18-bit resolution at 100 MHz sample rate (4 bits greater than state-of-the-art). Efficient auto-calibration routines will also be perfected. A compact, realtime hardware implementation will be built in the Phase I Option. V Corp has confirmed the technical efficacy of the LinComp processing methodology by testing with state-of-the-art converters. This compensation approach requires less hardware and provides much better dynamic range than competing linearity compensation methods. Very importantly, the LinComp processor will always exceed the state-of-the-art because it can easily be upgraded as new, more powerful DAC, ADC, and amplifier products become available. During Phase II, a compact LinComp DAC prototype will be developed with a high-speed PCI-based waveform generator and RF electronics to enable high IF direct digital synthesis (DDS).Anticipated Benefits/Commercial Applications: The LinComp approach overcomes the critical D/A conversion bottleneck which limits performance of state-of-the-art radio frequency transceiver systems. Virtually any high-performance modern electronic system will benefit from the LinComp DAC. Significant applications include enhancement of radar systems, wideband universal RF transceivers, specialized test equipment, and medical imaging systems.

This SBIR Phase II proposal develops two independent but complementary technologies that, when combined, provide up to an 8-fold increase in speed of analog-to-digital and digital-to-analog conversion with high-resolution, wide dynamic range performance. The Advanced Filter Bank (AFB) technology provides the architecture to combine state-of-the-art converters to dramatically increase the speed. The Linearity Error Compensation (LinComp) technology provides dramatic improvements in dynamic range, which enables very accurate conversion at high IF or RF frequencies. By eliminating stages of RF downconversion or upconversion, these technologies greatly accelerate the progress toward direct digitization or synthesis of wideband data directly at the antenna element. The breakthrough in converter performance afforded by the AFB and LinComp technologies will be demonstrated by developing fully-functioning prototypes combining these technologies. An open architecture prototype system will be developed provide a versatile platform to rapidly develop, test, and integrate the very latest converters using these technologies; target specifications include: 1) 12-bit ADC with 1.6 GHz sample rate (with direct sampling up to 800 MHz IF or RF); 2) 14-bit ADC with 800 MHz sample rate (with direct sampling up to 400 MHz IF/RF); 3) 16-bit ADC with 400 MHz sample rate (with direct sampling up to 200 MHz IF/RF); and 4) 14-bit DAC with 2 GHz sample rate (with direct digital synthesis up to 1 GHz IF/RF) In addition, a very compact prototype AFB ADC system will be developed for demonstration in the Navy Theater Wide (NTW) digital beam former (DBF) array or other system to test the AFB and LinComp technologies in an operationally relevant environment; this system will be designed to provide beyond state-of-the-art, extremely high speed and high resolution analog-to-digital conversion in a very compact package. Very importantly, the AFB and LinComp technologies have been specifically designed to avoid obsolescence because they can both be easily upgraded as new individual converters become available. This Phase II project is based upon two successful SBIR Phase I projects demonstrating the technical efficacy of these technologies in working lab breadboards. Numerous commercial and government entities have pledged a total of $490,000 of financial support for matching funds for this project; these entities will also provide technical support to help develop the technologies and a strong customer base for the commercialization in Phase III.The AFB and LinComp technologies overcome the critical analog-to-digital and digital-to-analog conversion bottleneck which limits performance of state-of-the-art radio frequency transceiver systems. Significant applications include enhancement of advanced radar systems, wideband universal RF transceivers, wideband Electronic Warfare transceivers, multi-beam adaptive digital beamforming array transceivers, linearization of full RF receive or transmit chains, smart radios for wireless communications (cellular and satellite), wide bandwidth modems, high performance special test equipment, software radios, and anti-Jam GPS Receivers. The AFB and LinComp technologies greatly accelerate the progress toward direct digitization or synthesis of wideband data directly at the antenna element.

Keywords:
analog-to-digital conversion, digital-to-analog conversion, high-resolution conversion, high-speed conversion, radio frequency communications, di