An all electronic passive millimetre wave imaging system

The need to develop passive millimetre wave imaging systems which have better spatial resolution and sensitivity, to offer powerful discrimination capabilities, is great. On the other hand, many deployment scenarios dictate the system footprint to be smaller than that of existing imagers. This dilemma may be resolved by replacing the bulky quasi-optics of existing imaging systems with two dimensional antenna arrays and electronic processors. This paper discusses initial design work for a demonstrator of an all electronic passive millimetre wave imager. This approach to the all electronic imaging system, endeavours to create ultimately an 'imager skin', which has essentially a two dimensional architecture, the minimum requirement for the collection of millimetre wave radiation for imaging. The physics of the imaging process and possible routes to electronic imaging are discussed. Possible arrays are investigated and a point spread function of the demonstrator imager is modelled. The results of using this imager system for a security scanning application are presented and conclusions about relevant technologies are given.