1. Qualitative analysis of cavities in the context of CEM

The electromagnetic compatibility problems encountered in many electronic devices are frequently amplified by the contribution of metallic cavities that help confine the fields. Such is the case of aircraft fuselages, where standing waves can settle, and where it is now important to understand the dynamics of amplitude and frequency. In this context, engineers in the aeronautical industry are encountering a growing population of electromagnetic field sources of extremely diverse origins. Cabin wiring networks are both sources of interference and collectors of disturbances produced by other wiring. There are also point sources such as cell phones and other equipment carried by air travellers. The four parts making up this first section initiate the qualitative approach to the physical problem of cavities, with a view to deepening it in the subsequent course of the article.