Abstract: A millimeter wave imaging system is disclosed which has wide applicability throughout transportation and related industries. For example, the system may be used to provide an aircraft pilot with an image of a landing field which is essentially unaffected by fog, rain, snow, blowing sand, etc. The system comprises an array of imaging elements as its fundamental component. Each of the imaging elements of the basic array comprises an antenna consisting of a pair of conductive elements and a non-linear circuit element connected thereacross. A image can then be formed responsive to millimeter-wave radiation without complex processing steps or any form of mechanical or electronic scanning.To increase the sensitivity of the imaging array system, a local oscillator signal may be mixed with the energy received from the field of view in each of the imaging elements by the non-linear circuit element. The oscillator used to provide the local oscillator signal can also be used to illuminate the field of view.

Abstract: A millimeter wave sensing device is disclosed comprising a local oscillator source generating a millimeter wave signal which is mixed with millimeter wave radiation reflected from or emitted by objects in a field of view. The mixing is performed in a staring array of mixer/detector elements which need not be mechanically or electronically scanned to generate signals responsive to the entire field of view. In a first embodiment of the invention, the device detects millimeter wave radiation emitted by or reflected from the object to be imaged. In a second embodiment of the invention, the oscillator used to provide the local oscillator signal is also used to illuminate the field of view. In the second embodiment of the invention, the oscillator signal is preferably linearly polarized, and a polarizing grid is used to separate the local oscillator signal and illumination beam and direct them in a simple and efficient manner.

Abstract: A millimeter wave object detection and location system is disclosed comprising a source generating a millimeter wave signal which is divided into an illumination beam, directed onto a field of view, and a local oscillator portion, mixed with radiation reflected from objects in the field of view. The mixing is performed in a staring array of mixer/detector elements which need not be mechanically or electronically scanned to generate signals responsive to the entire field of view. The detected signal from each element is directly responsive to a portion of the field of view. The oscillator signal is preferably linearly polarized, and a polarizing grid is used to separate the local oscillator signal and illumination beam and direct them in a simple and efficient manner. A twist reflector may also be used to rotate the polarization of a portion of the beam to direct it onto the mixer/detector array for mixing with the received signal from the field of view.