Fig. 1. System configuration

Fig. 2. Optical path of the focusing mirror

Fig. 3. Simulation results of image resolution

Fig. 4. Parameters of the antenna. (a) Radiation patterns of the antenna; (b) VSWR and gain of the antenna, in which the inset shows the antenna

Fig. 5. Image reconstruction and processing. (a) Image of the upper part of the body; (b) image of the lower part of the body; (c) image of the full body; (d) image after denoising; (e) image after contrast improving; (f) pseudo color image; (g) profile image; (h) image with hidden objects auto-marked

Fig. 6. Photos of the prototype

Fig. 7. Test equipment. (a) Resolution test chart; (b) samples

Fig. 8. Performance of the imaging system. (a) Background; (b) resolution test chart; (c) human body; (d) human body with powder; (e) human body with metal gun model; (f) human body with ceramic knife; (g) human body with liquid

Fig. 9. Resolution of the image