Non-Destructive Testing with Micro- and MM-Waves — Where We are — Where We Go

Test methods based on microwaves are well suited to characterize mainly electrically non-conducting materials and to detect and image defects in non-destructive and in many cases in contactless way. While in the past the often complicated and expensive microwave equipment prevented the widespread application of microwave methods this situation is now changing due to the increasing availability of low-cost high integrated microwave components. Microwave testing has found an important application in the field of security, e. g. to detect and image dangerous objects hidden under clothes. The principles of this technique can be applied in the domain of joining (e. g. welding of plastics or gluing plastic to plastic) for contactless detection of defects under cover layers.