JUNCTION RANGE FINDER

• US 3,732,567 A
• Filed: 09/21/1970
• Issued: 05/08/1973
• Est. Priority Date: 09/21/1970
• Status: Expired due to Term

• Current Assignee: Low George M Deputy Administrator of The National Aeronautics and Space, Marvin J. Frazier, N/a,, Ronald G. Sea, Sarto Morissette
• Original Assignee: Low George M Deputy Administrator of The National Aeronautics and Space, Marvin J. Frazier, N/a,, Ronald G. Sea, Sarto Morissette
• Inventors: Frazier, Marvin J., Low, George M. Deputy Administrator of the National Aeronautics and Space, N/a,, Morissette, Sarto, Sea, Ronald G.
• Primary Examiner(s): Borchelt, Benjamin A.
• Assistant Examiner(s): Tudor, Harold
• Application Number:
  US05/073,922
• Time in Patent Office: 960 Days
• Field of Search: 343/14,5SG,6.5R,17.5,6.8R
• US Class Current: 342/128
• CPC Class Codes: G01S 11/02 using radio waves G01S19/00 takes precedence

Abstract

An apparatus for locating an electrically nonlinear object and determining the distance to the object by transmitting an FM signal in the vicinity of the nonlinear object causing a signal of a higher harmonic to be reflected by the nonlinear object. A receiver is provided for receiving the higher harmonic reflected signal and comparing such with the initial exciting signal so as to produce a signal, the amplitude of which is directly proportional to the distance to the object.

Claims

1. Apparatus for locating an electrically nonlinear object comprising:

A. means for generating a frequency modulated exciting signal of a predetermined fundamental frequency;

B. a transmitting means for transmitting said exciting signal in the vicinity of said nonlinear object for causing a signal of a higher harmonic to be reflected by said nonlinear object;

C. a means located in close proximity to said nonlinear object for receiving said higher harmonic reflected signal;

D. filter means coupled to said receiving means for passing a predetermined harmonic portion of said received signal;

E. means coupled to said generating means for multiplying said exciting signal to produce a signal of the same frequency as said signal reflected by said nonlinear object and filtered by said filter means;

F. a first mixer for mixing said multiplied excited signal with said filtered reflected signal producing a combined signal;

G. amplifier means for amplifying said combined signal, H. a discriminator coupled to the output of said amplifying means for producing a signal having an amplitude directly proportional to the distance to said nonlinear object, and I. a limiter interposed between said first mixer and said discriminator for reducing unwanted amplitude modulations.

2. The apparatus as set forth in claim 1, wherein said means coupled to said generating means for multiplying said exciting signal includes;

A. a tripler coupled to said generating means for multiplying said exciting signal;

B. a local oscillator; and

C. a second mixer coupled to said tripler and oscillator for mixing the output of said local oscillator with the output of said tripler.