Fig. 1. Experimental sample diagram：(a) Sample design drawings；(b) Physical drawings of samples；(c) Cross-sectional view of the sample

Fig. 2. Time domain reflectometer reflection signals under different faults

Fig. 3. Schematic diagram of time-domain reflection of terahertz pulses

Fig. 4. Open circuit measurement method diagram of time-domain reflectometer

Fig. 5. Reflection signal diagram of metal wire convex defect with different parameters：(a) The α is 75% of the convex defects of metal wires with different line wi dths；(b) Different proportional convex defects when the w is 15 μm

Fig. 6. Reflection signal diagram of metal wire concave defect with different parameters:(a) The α is 75% of metal wire concave defects with different line widths;(b) Different proportions of concave defects when the w is 25 μm

Fig. 7. Measurement contact mode of time domain reflectometer for bimetal wire

Fig. 8. Reflected signal diagrams of different defect types of metal wires with different line widths： (a) Different defect types when the w is 10 μm； (b) Different defect types when the w is 15 μm； (c) Different defect types when the w is 20 μm； (d) Different defect types when the w is 25 μm

Fig. 9. Reflected signal diagram with different defect ratios of the same line width:(a) 25% defect ratio; (b) 50% defect ratio; (c) 75% defect rate

Fig. 10. Electromagnetic field distribution in microstrips

Fig. 11. Simulation structure diagram of single metal wire defect

Fig. 12. TDR simulation signals of convex defects：(a) Different w with same α； (b)Different α with same w

Fig. 13. TDR simulation signals of concave defects：(a) Different w with same α； (b) Different α with same w