Fig. 1. The progress of THz radar system（a）bandwidth，（b）resolution

Fig. 2. The block diagram of the 0.22 THz radar system

Fig. 3. Experimental model of 0.22 THz ISAR imaging

Fig. 4. Experimental scenario of 0.22 THz radar imaging

Fig. 5. THz radar imaging model

Fig. 6. Image reconstruction process using BP algorithm

Fig. 7. The flow chart of BP algorithm

Fig. 8. A photograph of the 0.22 THz radar system

Fig. 9. The corner reflectors are mounted on the turntable

Fig. 10. ISAR imaging result for a corner reflector

Fig. 11. ISAR result after phase compensation（single corner reflector）

Fig. 12. ISAR imaging result for two corner reflectors

Fig. 13. ISAR result after phase compensation（two corner reflectors）

Fig. 14. ISAR result using RD algorithm