Optimization of a fast scanning millimetre-wave short range SAR imaging system

This paper presents the development of a W-band short range imaging system for security and non-destructive testing applications, which uses an unfocused measurement setup employing SAR algorithms in order to focus the image numerically. The active imaging system offers the possibility to get a broadband frequency response from each pixel in the measurement plane. For real-time applications a fast scanning, monostatic virtual antenna concept has been developed and optimized. The monostatic setup is demonstrated in two different configurations, on the one hand using a quasioptical, broadband diplexer with high decoupling between transmitter and receiver channel and on the other hand a very compact setup using a commercially available high directivity waveguide coupler. The measurement setups are compared with special respect to their RF-performance. Experimental results on specific test objects are presented to prove the performance of the fast short range SAR imaging system.