Object detection and location system

A millimeter wave object detection, location and velocity indicating system, comprising:

• means for emitting a beam of millimeter-wave radiation, the frequency of which is varied in a predetermined manner as function of time;
• means for directing said beam onto a field of view;
• an array of detectors for detecting radiation reflected from objects in said field of view;
• an array of sources of millimeter wave radiation, arranged to evenly illuminate said array of detectors with a local oscillator signal;
• said detectors each further comprising means for mixing said local oscillator signal with radiation reflected from objects in the field of view and means for providing an output signal responsive to said means for mixing;
• and
• signal processing means, for:
• determining the direction of said objects with respect to said array of detectors, responsive to identification of the ones of said detectors providing said output signals;
• determining the distance of said objects from said array of detectors, responsive to measurement of the time elapsed between emission of the reflected radiation and its detection;
• and
• determining the velocity of said objects by determining the relative frequency shift of the reflected radiation.

Method for generating a millimeter-wave image responsive to objects in a field of view, comprising the steps of:

• employing an array of oscillator sources to generate a beam of millimeter-wave energy, the frequency of which is varied according to a predetermined function of time,
• transmitting a first minor portion of said beam toward an array of mixer/detector elements, such that individual ones of said oscillator sources illuminate corresponding portions of said array,
• directing a second major portion of said beam onto the field of view, such that individual ones of said oscillator sources illuminate corresponding portions of the field of view,
• focusing energy from said major portion of said beam reflected from objects in the field of view onto the array,
• mixing the reflected energy with the minor portion of the beam individually in the elements of said array,
• detecting difference-frequency signals resulting from said mixing step with respect to each of the elements of said array,
• analyzing said detected difference frequency signals to determine the relative direction and distance of said objects with respect to said array of elements, and
• generating an image of said objects responsive to said analyzing step.