@article{wyers_morton_sollner_kelley_franzon_2016, title={A Generally Applicable Calibration Algorithm for Digitally Reconfigurable Self-Healing RFICs}, volume={24}, ISSN={1063-8210 1557-9999}, url={http://dx.doi.org/10.1109/TVLSI.2015.2424211}, DOI={10.1109/tvlsi.2015.2424211}, abstractNote={A generally applicable calibration technique for digitally reconfigurable self-healing radio frequency integrated circuits based on a hybrid of the Nelder-Mead and Hooke-Jeeves direct search algorithms is presented. The proposed algorithm is applied to the multiobjective problem of gain error and phase error minimization for a self-healing phase rotator test case. For the 8-D phase rotator calibration problem, we show that the proposed hybrid Nelder-Mead and Hooke-Jeeves calibration algorithm is capable of reducing the gain error and phase error of the phase rotator output to less than a maximum of 0.5 dB and 2°, respectively, relative to the chosen gain and phase targets. A 3-GHz self-healing phase rotator test chip was fabricated in a 45-nm silicon-on-insulator CMOS process, and the measured data were obtained to validate the performance of the proposed calibration algorithm.}, number={3}, journal={IEEE Transactions on Very Large Scale Integration (VLSI) Systems}, publisher={Institute of Electrical and Electronics Engineers (IEEE)}, author={Wyers, Eric J. and Morton, Matthew A. and Sollner, T. C. L. Gerhard and Kelley, C. T. and Franzon, Paul D.}, year={2016}, month={Mar}, pages={1151–1164} }
 @article{wyers_steer_kelley_franzon_2013, title={A Bounded and Discretized Nelder-Mead Algorithm Suitable for RFIC Calibration}, volume={60}, ISSN={["1558-0806"]}, DOI={10.1109/tcsi.2012.2230496}, abstractNote={This paper describes a calibration technique for noisy and nonconvex circuit responses based on the Nelder-Mead direct search algorithm. As Nelder-Mead is intended for unconstrained optimization problems, we present an implementation of the algorithm which is suitable for bounded and discretized RFIC calibration problems. We apply the proposed algorithm to the problem of spurious tone reduction via VCO control line ripple minimization for a PLL operating at a frequency of 12 GHz. For this nonconvex calibration test case, we show that a gradient descent-based algorithm has difficulty in reducing the VCO control line ripple, while the proposed algorithm reduces the relative power of the first harmonic reference spurs by at least 10 dBc and effectively enables design complexity reduction in the supporting analog calibration circuitry.}, number={7}, journal={IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS}, author={Wyers, Eric J. and Steer, Michael B. and Kelley, C. T. and Franzon, Paul D.}, year={2013}, month={Jul}, pages={1787–1799} }