RT-Duroid® laminates are polytetrafluoroethylene (PTFE)-based composites reinforced with ceramic or glass microfiber fillers, widely used in high-frequency and microwave applications. In specific environments, such as space or nuclear facilities, these materials may be exposed to ionizing radiation. Understanding the effects of such exposure on the physical and electrical properties of RT-Duroid® materials is crucial for ensuring their performance and reliability.