High-frequency PCBs are primarily made of materials with high dielectric constants and low high-frequency losses. Currently, fluorinated dielectric substrates, such as polytetrafluoroethylene (PTFE, commonly known as Teflon), are widely used in high-frequency applications above 5 GHz due to their excellent performance. FR-4 or PPO substrates are also commonly used for products operating between 1 GHz and 10 GHz.
