Resonant transformers are electrical devices that transfer energy between two circuits through electromagnetic induction, utilizing resonance to enhance efficiency. They operate at a specific frequency, allowing for maximum energy transfer between the primary and secondary coils. This design minimizes energy loss, making them suitable for applications like wireless power transmission and radio frequency systems. These transformers often use a combination of inductors and capacitors to create a resonant circuit. By tuning the circuit to the same frequency, the energy can be transferred more effectively. Resonant transformers are commonly found in technologies such as wireless charging and RFID systems.