High-Q and miniaturized complementary split ring resonator-loaded substrate integrated waveguide microwave sensor for crack detection in metallic materials

In this paper, a high-Q and miniaturized complementary split ring resonator (CSRR)-loaded substrate integrated waveguide (SIW) microwave sensor for the detection of cracks in metallic materials is presented. A SIW and CSRR with a high Q are used for achieving high sensitivity. In addition, by loading the CSRR on the SIW, the sensor is miniaturized and can be operated below the cut-off frequency of the SIW. The proposed sensor exhibits a frequency shift of 220 MHz for a 100-mu m crack and 600 MHz for a 1-mm crack. (C) 2014 Elsevier B.V. All rights reserved.