Research of Crack Defect Detection in Metal Pipes Based on Microwave Antenna Array

This study evaluates the feasibility of using antenna array to detect crack defects in metal pipes. Antenna arrays are set at port a pipe radial direction, and microwave signal can be effectively coupled into pipe. It produce orbital angular momentum (OAM) waves. The cracks will change transmission characteristics, they inspected by time domain reflectometry (TDR) vector network analyzer (VNA). By studying characteristics current on inner surface pipe, linearly polarized TE11 mode microwaves for inspection was preliminarily verified. Three galvanized pipes with an diameter 8 cm total length about 270 were used experiment. Axial slits circumferential simulate crack, respectively. penetrated wall breach approximately 10 cm × 0.7 . experimental results demonstrated that direction both axial slit through TDR standing wave ratio (SWR) port, especially effective slit. provides new method defect evaluation.