All-in-one device uses microwave power for defense, medicine An invention from Purdue University innovators may provide a new option to use directed energy for biomedical and defense applications. (Stock image) WEST LAFAYETTE, Ind. – An invention from Purdue University innovators may provide a new option to use directed energy for biomedical and defense applications. The Purdue invention uses composite based nonlinear transmission lines (NLTLs) for a complete high-power microwave system, eliminating the need for multiple auxiliary systems. The interest in NLTLs has increased in the past few decades because they offer an effective solid-state alternative to conventional vacuum-based, high-power microwave generators that require large and expensive external systems, such as cryogenic electromagnets and high-voltage nanosecond pulse generators.