Microwave Near-Field Imaging with Open-Ended Waveguide—Comparison with Other Techniques of Nondestructive Testing

The results of an experimental study of microwave imaging with an openended waveguide at 30 GHz for NDE of dielectric materials are presented. Using a hybrid measurement method, the near-field point spread function is investigated. Improvement of sensitivity and resolution via deconvolution also is discussed. A comparison of results obtained with more prominent NDE methods as ultrasonics, X-rays, and thermal waves demonstrates the performance of the technique.