Patent attributes
An imaging millimeter wave radar system. The system includes a millimeter wave transmitter transmitting a frequency scanned millimeter beam that is narrow in the scanned direction and wide in a direction perpendicular to the scanned direction. The system includes a receive antenna and a Rotman type lens for forming a one-dimensional image in the perpendicular direction of targets in the antennas field of view based on millimeter wave radiation reflected from the targets. A computer creates a two dimensional image based on the scanning direction of the transmit beam of the transmit antenna and the one dimensional image from the receive antenna. Distance to the target is determined based on difference in frequency of the transmit signal and the receive signal. Thus, a three dimensional view of the systems field of view is determined by the system. This view can be displayed on a monitor using color to represent target distance. In a preferred embodiment the scanned direction is the vertical direction and the receive antenna forms a horizontal image from signals reflected from targets in the field of view. In this preferred embodiment the transmit antenna is a variable frequency millimeter wave single channel wave guide antenna operating in the 78 GHz to 81 Ghz spectral range to produce a scanning range of 10 degrees and a scanning rate of 60 Hz. The receive antenna is a multi-channel (176 channels) strip-line antenna also operating in the 78 GHz to 81 GHz spectral range, which with the Rotman lens, provides 192 horizontal pixel resolution.
