Adaptive impedance matching and antenna tuning for green software-defined and cognitive radio

Abstract

???This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder." ???Copyright IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.???Impedance matching between the power amplifier and antenna is crucial for efficient power transfer in a green transmitter. A single antenna with a software-configurable tuning unit can serve the functions of multiple antennas which are otherwise required by multistandard wireless communications. Impedance matching and tuning must be adaptive and in real time for fast varying frequencies and surroundings of mobile communications. Small size and low power consumption must also be met in such tuning systems for mobile phones and terminals. This paper overviews automatic antenna tuning for modern and future generation mobile communications. Recent advances in impedance monitoring methods, fast tuning algorithms and programmable matching systems are discussed. Latest effort in integrating automatic impedance tuning systems on a silicon chip is also introduced

Optimization of power-amplifier load impedance and waveform bandwidth for real-time reconfigurable radar

“…The results of Part A show that the optimum ACPR value under the PAE constraint was less than the specified limit of −27.5 dBc, so the interval halving was enacted toward the upper end of the range. The value of L was held constant at the found optimum value of L = 0.52 /−17.3 • and the value of B was set to halve between 12 of 12-20 MHz. Fig.…”

“…Sun and Lau have demonstrated the use of genetic algorithms for antenna impedance tuning [7,8], and the literature also presents approaches such as fuzzy control [9], neural networks [10], and least-squares optimization [11] for real-time impedance tuning. Sun et al suggest reconfigurable matching networks as a tool for providing high-efficiency transmitters [12]. Kingsley and Guerci demonstrate an adaptive amplifier module capable of adjusting to optimize for different requirements, such as PAE, minimization of third-order intermodulation, and output power [13].…”

Wearable self‐tuning antenna for emergency rescue operations

“…However, these designs do not fully consider the effect of variations in the antenna's operating conditions due to the wearer re-orientation and movement. On the other hand, closed-loop self-tuning impedance networks were investigated for other applications [9,10]. In the open literature, different designs of self-tuning circuits are reported.…”

Circuit optimization algorithms for real-time spectrum sharing between radar and communications

“…An adaptive impedance tuner is presented by Deve, who demonstrates tuning from 1 to 3 GHz [3]. Sun discusses the criticality of minimizing the number of iterations in impedance tuning algorithms [4]. Real-time impedance matching is demonstrated in the literature [5,6], and Qiao demonstrates a tunable amplifier using a genetic algorithm for low-power communication applications [7].…”