Improvements in or relating to millimeter and sub-millimeter wave radar-radiometric imaging

Abstract

An antenna is provided that is configured to implement a combined radar and radiometric imaging method. The antenna comprises: a bearing device on which is rigidly mounted: rotating waveguide adapter which provides the output for the antenna; an electromechanical drive, the output shaft of which is defined as the main axis of rotation for the antenna and a position sensor. The antenna further comprises an antenna rotor, the rotation of which is configured to be controlled by the out-put shaft of the electromechanical drive of the bearing device. The antenna rotor comprises: at least one 2D diffraction grating; planar dielectric waveguide connected over a diffraction field to the 2D diffraction grating; a linear waveguide turn; and a feed adapter.

Description

technical field [0001] The present invention relates to microwave imaging equipment and is designed to be used when operating in active (when transmitting a microwave signal and receiving a portion of this signal reflected from an observed object) and / or passive (when receiving natural external emissions) modes On-line millimeter or submillimeter wave imaging of objects. The method, as well as the antenna and system implementing the method, can be used in particular to obtain images of people during customs supervision, to detect various objects on the human body hidden under clothing, or to measure temperature for medical diagnosis. Background technique [0002] Currently, remote surveys of various environments are frequently performed using methods (passive and active) implemented in the microwave band. These methods are based on the correlation between the intensity (in passive mode) or backscattering values ​​(in active mode) of the intrinsic radiation-thermal radiation...

AI Technical Summary

Problems solved by technology

[0015] Disadvantages of systems with beamforming matrices in the millimeter and submillimeter bands include: difficulties in positioning a large number of feed elements (measurement channels) in the focal plane of the antenna when physically limited dimensions of the unit feed elements exist; Problematic establishment of beamforming matrices with spatially overlapping beams when implementing highly directional antennas; and high overall cost of the system in the quadratic dependence B on the number of image elements B for each coordinate 2 aspect correlates with the increased number of receive channels

The disadvantage of the system is the principle of reciprocating antenna movement during scanning, which limits the imaging speed

Another disadvantage includes the limited sector of viewing angle associated with the operating frequency bandwidth

Another disadvantage of the system is that the information that can be gathered from the system is limited by, for example, operation in only one (active) mode, thereby limiting the ability to detect objects with complex and variable signature signatures due to arising from and dependent on perspective

Images