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 (or the combination of these devices in the complete RF chain) 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 300 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 implementing the digital processing in realtime FPGA hardware, demonstrating efficient auto-calibration routines, an testing the processor on a combination of devices in an RF chain. The auto-calibration routines will be built in FPGA hardware in the Phase I Option. V-Corp has confirmed the technical efficacy of the LinComp processing methodology by testing with state-of-the-art digital-to-analog and analog-to-digital converters. This compensation approach requires less hardware, provides much better dynamic range, and provides compensation over a wider bandwidth than competing linearity compensation methods (such as phase-plane compensation and dither). 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 waveform generator and RF electronics to enable high IF direct digital synthesis (DDS).
Benefits: 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.
Keywords: high-resolution, high-speed, linearity compensation, digital-to-analog conversion, analog-to-digital conversion, radio frequency communications, amplifiers
