The increasing complexity of wireless communication systems coupled with shorter design cycles has increased the need for modeling and design methodologies that are both accurate and fast. It is, however, extremely difficult to meet these contradictory requirements using conventional computer-aided design (CAD). Over the past few decades, artificial intelligence (AI) and machine learning (ML) techniques have gained popularity in the RF and microwave community and are increasingly being used. Particularly in recent years, there has been an increase in the use of AI and ML methods for the modeling and design of wireless devices, circuits, and systems, including active device modeling, power amplifier modeling and digital predistortion, passive circuit design and optimization, active circuit design and optimization, wireless power transfer, wireless systems design and optimization and more.The special issue contains 25 papers that address a variety of topics including AI and ML based device modeling, circuit design and optimization, circuit modeling and digital predistortion, and so forth. Several outstanding contributions to modeling and characterization of electronic devices based on AI and traditional techniques are given. [1][2][3][4] Additionally, RF circuit design can benefit from AI and ML techniques, including active circuit design, such as PAs 5-9 and LNA, 10,11 and passive circuit design, such as filters. 12 The use of AI methods has also been extended to the modeling and predistortion of dynamic characteristic of circuits and systems, for example, RF PA modeling, [13][14][15] digital predistortion of high frequency transmitters, 16 suppressing nonlinearity in circuits, 17,18 and analyzing circuit crosstalk and phased array errors. 19,20 Furthermore, AI methods can also be used to detect circuit defects and cracks. 21,22 Along with the aforementioned topics, AI and machine learning methods are applied to organic transistors, solar cells, and digital circuit design. [23][24][25] From the device level up to the system level, this special issue explores the different branches of knowledge that relate to AI and ML for the modeling and design of wireless devices, circuits, and systems. It is our intention to provide a comprehensive overview of these topics from the reader's point of view as well as useful hints for overcoming the technological challenges of the future.As Guest Editors, we would like to express our gratitude to Prof. Giovanni Crupi (Editor-in-Chief of Int J Numer Model) for facilitating this special issue. In addition, we would like to thank all authors for their high-quality contributions, as well as all reviewers who took the time and effort to examine the submissions carefully. Readers of the journal will find the presented works of interest, and we hope that this special issue will contribute to raising awareness and popularizing AI and ML techniques as valuable methodologies for the modeling and designing of electronic devices, circuits, and systems.
