Imaging millimeter wave radar system

• US 7,019,682 B1
• Filed: 04/12/2005
• Issued: 03/28/2006
• Est. Priority Date: 04/12/2005
• Status: Expired due to Fees

• Current Assignee: Trex Enterprises Corporation
• Original Assignee: Trex Enterprises Corporation
• Inventors: Kolinko, Vladimir, Saunders, Robert C., Woodbridge, Eric, Louberg, John
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US11/104,920
• Time in Patent Office: 350 Days
• Field of Search: 342/22, 342 25 A- 25 E, 342/26.R, 342/26.A, 342/26.B, 342/27, 342/29, 342/89, 342/90, 342/175, 342/176, 342179-183, 342/195, 342/197
• US Class Current: 342/22
• CPC Class Codes: G01S 13/89 for mapping or imaging
• CPC Class Codes: G01S 13/933 of aircraft or spacecraft
• CPC Class Codes: G01S 2013/0245 Radar with phased array antenna
• CPC Class Codes: G01S 7/03 Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
• CPC Class Codes: H01Q 21/005 Slotted waveguides arrays
• CPC Class Codes: H01Q 25/008 lens fed multibeam arrays

Abstract

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.

Claims

1. An imaging millimeter wave radar system comprising:

A) a millimeter wave transmit antenna transmitting a frequency scanned millimeter beam that is narrow in the scanned direction and wide in a direction perpendicular to the scanned direction;

B) a receive antenna comprising a Rotman-type lens system for forming a one-dimensional image in the perpendicular direction of targets in the receive antenna field of view based on millimeter wave radiation transmitted by said transmit antenna and reflected from the targets;

C) a computer processor for creating a three-dimensional image information based on;

1) the scanning direction of the transmit beam of the transmit antenna,

2) the one-dimensional images from the receive antenna, and

3) distances to the targets based on differences in frequency of the transmit signal and the receive signal.

2. The system as in claim 1 and further comprising a monitor for displaying three-dimensional images based on said three-dimensional image information.

3. The system as in claim 1 wherein said computer processor is programmed with software to display distances to targets as colors.

4. The system as in claim 1 wherein said transmit antenna is a single channel slotted waveguide antenna.

5. The system as in claim 1 wherein said receive antenna is a multi-channel slotted strip-line antenna.

6. The system as in claim 1 wherein said scanned direction is vertical.

7. The system as in claim 6 wherein said perpendicular direction is azimuthal.

8. The system as in claim 1 wherein 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.

9. The system as in claim 8 wherein the receive antenna is a multi-channel strip-line antenna also operating in the 78 GHz to 81 GHz spectral range.

10. The system as in claim 9 wherein said system is configured to provide at least 190 pixel resolution in the azimuthal direction.