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This paper presents a frequency-selective RF vector predistortion linearization system for RF multicarrier power amplifiers (PAs) affected by strong differential memory effects. Differential memory effects can be revealed in two-tone experiment by the divergence for increasing tone-spacing of the vector Volterra coefficients associated with the lower and upper intermodulations tones. Using large-signal vector measurement with a large-singal network analyzer, a class-AB LDMOS RF PA is demonstrated to exhibit a strong differential memory effect for modulation bandwidth above 0.3 MHz. New frequency-selective RF and baseband predistortion linearization algorithms are proposed to separately address the linearization requirements of the interband and inband intermodulation products of both the lower and upper sidebands. Theoretical verification of the algorithms are demonstrated with MATLAB simulations using a Volterra/Wiener PA model with memory effects. The baseband linearization algorithm is next implemented in a field-programmable gate array and experimentally investigated for the linearization of the class-AB LDMOS PA for two carrier wideband code-division multiple-access signals. The ability of the algorithm to selectively linearize the two interband and four inband intermodulation products is demonstrated. Adjacent channel leakage ratio of up to 45 dBc for inband and interband are demonstrated experimentally at twice the typical fractional bandwidth.

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Fuelled by rapid growth in communications technology, silicon heterostructures and related high-speed semiconductors are spearheading the drive toward smaller, faster and lower power devices. High-Speed Heterostructure Devices is a textbook on modern high-speed semiconductor devices intended for both graduate students and practising engineers. This book is concerned with the underlying physics of heterostructures as well as some of the most recent techniques for modeling and simulating these devices. Emphasis is placed on heterostructure devices of the immediate future such as the MODFET, HBT and RTD. The principles of operation of other devices such as the Bloch Oscillator, RITD, Gunn diode, quantum cascade laser and SOI and LD MOSFETs are also introduced. Initially developed for a graduate course taught at Ohio State University, the book comes with a complete set of homework problems and a web link to MATLAB programs supporting the lecture material.

With increasingly low-cost and power-efficient RF electronics being demanded by today's wireless communication systems, it is essential to keep up to speed with new developments. This book presents key advances in the field that you need to know about and emerging patterns in large-signal measurement techniques, modeling, and nonlinear circuit design theory supported by practical examples. Topics covered include: • novel large-signal measurement techniques that have become available with the introduction of nonlinear vector network analyzers (NVNAs), such as the LSNA, PNA-X, and SWAP • direct extraction of device models from large-signal RF dynamic loadlines • characterization of memory effects (self-heating, traps) with pulsed RF measurements • interactive design of power-efficient amplifiers (PAs) and oscillators using ultra-fast multi-harmonic active load-pull • Volterra and poly-harmonic distortion (X-parameters) behavioral modeling • oscillator phase noise theory • balancing, modeling, and poly-harmonic linearization of broadband RFIC modulators • development of a frequency-selective predistorter to linearize PAs