Abstract: The present invention presents a flexible, stepped frequency, radar based, imaging inspection system. The imaging inspection system can be used in airports, seaport sites, borders, postal processing centres, and sensitive sites. It comprises a millimetre-wave Stepped Frequency Continuous Wave (SFCW) radar module (2) connected to a transmitting channel and a receiving channel. The transmitting channel may comprise a frequency upconvertor (8) and the receiving channel may comprise a frequency downconvertor (10). A digital signal processing unit (14) reconstructs a conductivity profile and a permittivity profile of an object under test (OUT) from measurement data collected via a phase-array antenna or a translational stage (18) based on synthetic aperture focusing (SAF).

Abstract: A multi-view planar near-field scattering tomography system is provided herein. In one aspect the system is developed based on the reformulated signal subspace approach. Utilized for solving the electromagnetic inverse scattering problem, the signal subspace approach is reformulated. The present invention pertains to a computationally efficient approach to an electromagnetic inverse scattering-based permittivity profile estimation technique. In a second aspect, the system is developed at the millimeter-wave and THz frequency range to ensure accuracy by eliminating the multipath effects and without the need for an Anechoic chamber or water as a background medium for clinical, security, and manufacturing applications.

Abstract: A mechanism for achieving symmetrical stress loads on operating optical fibers (16) held in fiber optic arrays includes, in one embodiment, the provision of a pair of non-operating or dummy fibers(26), each located outboard of the outermost or curb fibers(16?) of the array. All of the fibers, whether operating or dummy, are held in corresponding grooves (18, 24) in a substrate (12). A cover plate (14) may be positioned thereover while a low stress glue or potting compound (22) is introduced or applied so as to completely encapsulate the fibers. The glue or potting compound will symmetrically surround all of the operating fibers whereby not only any inboard operating fibers (16?), but also the outboard operating curb fibers (16?), are symmetrically encapsulated. In this manner all of the operating fibers are subject to the same stresses and consequently will exhibit essentially the same polarization maintaining behavior.

Abstract: A mechanism for achieving symmetrical stress loads on operating optical fibers (16) held in fibre optic arrays includes, in one embodiment, the provision of a pair of non-operating or dummy fibres(26), each located outboard of the outermost or curb fibres(16?) of the array. All of the fibres, whether operating or dummy, are held in corresponding grooves (18, 24) in a substrate (12). A cover plate (14) may be positioned thereover while a low stress glue or potting compound (22) is introduced or applied so as to completely encapsulate the fibres. The glue or potting compound will symmetrically surround all of the operating fibres whereby not only any inboard operating fibres (16?), but also the outboard operating curb fibres (16?), are symmetrically encapsulated. In this manner all of the operating fibres are subject to the same stresses and consequently will exhibit essentially the same polarization maintaining behavior.