Guest Editorial Special Section on IMEKO 2011 International Workshop on ADC Modeling, Testing and Data Converter Analysis and Design and the IEEE 2011 ADC Forum

High-Efficiency Cascade Modulators for the Next Generation Software-Defined-Radio Mobile Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A. Morgado, R. del Rı́o, and J. M. de la Rosa xxxx A Beam Phase and Energy Measurement Instrument Based on Direct RF Signal IQ Undersampling Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S. Tang, L. Zhao, S. Liu, X. Hao, W. Wu, and Q. An xxxx Audio Telecom ADC Featuring Click-Free Gain Control Technique, Dithering Insertion, and Idle Tone Shifting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . F. Rizzo, S. S. Somayajula, D. Zito, R. Saletti, and R. Becker xxxx Improvement in Spectral Properties of Quantization Noise of Harmonic Signal Using Multiresolution Quantization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M. Kamenský, K. Kováč, and G. Války xxxx A Power-Optimal Design Methodology for High-Resolution Low-Bandwidth SC Modulators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S. Porrazzo, F. Cannillo, C. Van Hoof, E. Cantatore, and A. H. M. van Roermund xxxx Exploiting Pseudorandom Sequences to Enhance Noise Immunity for Air-Coupled Ultrasonic Nondestructive Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . M. Ricci, L. Senni, and P. Burrascano xxxx