Advanced Linearizer for Digital Receivers

This project demonstrates an advanced linearization algorithm for ultra high-performance digital receiver systems to dramatically reduce harmonic and intermodulation distortion by up to 30 dB over a wide range of input frequencies, signal types, and amplitudes. The real-time processing significantly improves the performance of analog-to-digital converters and the combination of devices in an RF receiver chain (e.g., amplifiers, mixers, converters). This technology improves the dynamic range, which enables very accurate and efficient sampling of wideband signals at very high intermediate frequencies (IF) or directly at high RF. This eliminates stages of downconversion electronics and thereby lowers the power, mass, and cost while improving performance. The linearizer is based on V Corp’s proprietary phase-shift functional model which has been successfully implemented with devices that exhibit traditional nonlinear characteristics (e.g., second and third order harmonics and intermodulation due to compression effects). The advanced linearizer uses a higher order curve to model the nonlinear distortion profile, which is more accurate and stable than second and third order polynomials. This advancement provides a very accurate model of the distortion transfer function such that errors can be subtracted out. The architecture will always exceed state-of-the-art because it can easily be upgraded as new, more powerful converter and receiver devices become available. During Phase I, V Corp will demonstrate the advanced linearizer technique via real and simulated data from various commercial-off-the-shelf A/D converters. During Phase II, a real-time prototype will be implemented and tested for use with advanced digital receivers.