Apparatus and method to detect radar radome obstruction

• US 5,485,159 A
• Filed: 08/24/1994
• Issued: 01/16/1996
• Est. Priority Date: 08/24/1994
• Status: Expired due to Fees

• Current Assignee: Delphi Technologies, Inc. (Aptiv PLC)
• Original Assignee: Delco Electronics Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Henderson, Mark F., Zhang, Zhaohong
• Primary Examiner(s): Jordan, Charles T.
• Assistant Examiner(s): Wesson, Theresa M.
• Application Number:
  US08/299,168
• Time in Patent Office: 510 Days
• Field of Search: 342/165, 342/173, 342/174, 342/169, 342/170, 340/580
• US Class Current: 342/165
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 7/4004 of parts of a radar system
• CPC Class Codes: G01S 7/4039 of sensor or antenna obstruction, e.g. dirt- or ice-coating

Abstract

Detection means having thin wire electrodes that are placed on the outer surface of a radome that shelters an antenna used for transmitting and/or receiving intelligence in the form of radio waves, such as those microwave signals used in radar, especially radar that is used for a vehicle. The thin wire electrodes are placed on the radome surface in a way which will not change antenna characteristics. The electrodes measure the electrical resistance of the obstruction material, such as wet mud, that may find its way onto the outer surface of the radome during the operation of the vehicle and that may reduce the sensitivity of the radar'"'"'s receiver so as to prevent it from recognizing otherwise discernable echo information. The detection means, upon detecting a predetermined electrical resistance of the obstruction material, provides a signal that is routed to the operator that is indicative that the radar performance may have degraded beyond an acceptable limit.

Claims

1. An antenna system comprising:

(a) an antenna for transmitting and receiving signals;

(b) a radome sheltering said antenna and having an outer surface susceptible to accumulating obstruction material which has an electrical resistance characteristic;

(c) a pair of spaced-apart electrodes affixed to said outer surface of said radome;

(d) means connected to the electrodes for measuring the electrical resistance characteristic of said obstruction material accumulated between said spaced-apart electrodes;

(e) means for correlating the measured electrical resistance characteristic to a degree of attenuation of said transmitted and received signals due to the presence of said obstruction material on said radome; and

(f) means for providing a warning indication when a surface impedance measurement corresponding to a predetermined degree of signal attenuation is reached.

2. The antenna system of claim 1, wherein the antenna has an electric field, and the electrodes are arranged to be perpendicular to said electric field.

3. A method for detecting and responding to signal attenuation of an antenna system having an antenna which is sheltered by a radome with an outer surface susceptible to accumulate obstruction material, said method comprising the steps of:

(a) affixing spaced-apart electrodes onto said outer surface of said radome;

(b) connecting an impedance measuring means to said spaced-apart electrodes and measuring the surface impedance between said spaced-apart electrodes;

(c) correlating the measured surface impedance to a degree of signal attenuation of said antenna system due to the presence of said obstruction material on said radome; and

(d) terminating said operation of said antenna system when a surface impedance measurement corresponding to a predetermined degree of signal attenuation is reached.