This book summarizes the physical models and simulation methods of PIM explored in national and enterprise research projects in which the author participated. Passive intermodulation (PIM) is a vital parameter in the design of radio frequency (RF) communication systems. Closed-form PIM equations and full-wave PIM simulation methods are achieved by utilizing the linearity–nonlinearity separation and one-way coupling approximation theories. Additionally, the behavior model is briefly discussed at the end of the book. This book will benefit researchers, engineers, and graduate students in the fields of RF nonlinearities, telecommunications, and electromagnetic simulation.

Xiaolong Zhao received his B.E. degree in microelectronics and Ph.D. degree in electronics science and technology, Xi’an Jiaotong University, in 2012 and 2017, respectively. During his graduate studies, he participated in a national project and began to study the PIM effects in RF components. From September 2016 to December 2016, he studied as a visiting student at University of Michigan-Shanghai Jiao Tong University Joint Institute. From 2017 to 2018, he worked as an engineer engaged in signal distortion solution for the smartphone at Huawei Technology Co., Ltd. After that, he joined Xi’an Jiaotong University as an assistant professor. In 2022, he was promoted to an associate professor in the School of Microelectronics at Xi’an Jiaotong University. His research interests include nonlinear interference modeling and electromagnetic simulation for RF components and semiconductor-devices and systems for nuclear radiation detection.