BINARY BEAM SYSTEM

• US 3,863,258 A
• Filed: 06/28/1973
• Issued: 01/28/1975
• Est. Priority Date: 09/14/1971
• Status: Expired due to Term

• Current Assignee: William H. Clark
• Original Assignee: William H. Clark
• Inventors: Clark, William H.
• Primary Examiner(s): Wilbur, Maynard R.
• Assistant Examiner(s): Berger, Richard E.
• Application Number:
  US05/374,366
• Time in Patent Office: 579 Days
• Field of Search: 343/113R 324/13D
• US Class Current: 342/424
• CPC Class Codes: G01S 3/48 the waves arriving at the antennas being continuous or intermittent and the phase difference of signals derived therefrom being measured

Abstract

An interferometric direction finder system for radio waves employing unique logic using the phase difference between signals received by one or more pairs of antennas to generate a multiple digital code representing direction. A preferred implementation employs product detectors for deriving the sum and difference signals, used for unique encoding.

Claims

1. In a digital direction finding system, a pair of spaced apart antennas, means deriving squared sum and squared difference signals from said antennas and producing a digit of the code representing the greater amplitude between the squared sum and squared difference signals, means deriving phase shifted squared sum and squared difference signals from said antennas where an output of one antenna is shifted in phase by a fixed displacement, and producing another digit of said code representing the greater amplitude between the phase shifted squared sum and squared difference signals, means comparing the absolute amplitude of the squared sum minus squared difference signals with the absolute amplitude of the squared sum minus squared difference phase displaced signals and producing an additional digit of the code representing the greater of the absolute amplitudes, and means producing an additional lower digit of the code by comparing the smaller of said absolute amplitudes with a preset fixed amplitude reference signal.

2. In a digital direction finding system, a pair of spaced apart antennas, means deriving squared sum and squared difference signals from said antennas and producing a digit of the code representing the greater amplitude between the squareD sum and squared difference signals, means deriving phase shifted squared sum and squared difference signals from said antennas, where an output of one antenna is shifted in phase by a fixed displacement, and producing another digit of said code representing the greater amplitude between the phase shifted squared sum and squared difference signals, and means comparing the absolute amplitude of the squared sum minus squared difference signals with the absolute amplitude of the squared sum minus squared difference phase displaced signals and producing an additional digit of the code representing the greater of the absolute amplitudes, and means deriving the ratio signal between said first mentioned difference signal and said second mentioned difference signal and producing succeeding digits representing the greater of the amplitudes of said ratio signal and fixed reference signals.

3. In a digital direction finding system, a pair of spaced apart antennas, a first product detector energized by said antennas for deriving a signal proportional to the cosine of the phase angle displacement between the antenna signals, a fixed phase shifter and second product detector energized by said antennas for deriving a signal proportional to the sine of the phase angle, means responsive to the amplitude, polarity, and relative amplitudes of the sine and cosine signals for producing a digital code representative of the spatial direction of a radio wave referenced to said antennas, said means including means for comparing the amplitudes of the sine and cosine signals to fixed amplitude reference signals to produce lower order digits of said code.

4. In a digital direction finding system, a pair of spaced apart antennas, a first product detector energized by said antennas for deriving a signal proportional to the cosine of the phase angle displacement between the antenna signals, a fixed phase shifter and second product detector energized by said antennas for deriving a signal proportional to the sine of the phase angle, means responsive to the amplitude, polarity, and relative amplitudes of the sine and cosine signals for producing a digital code respresentative of the spatial direction of a radio wave referenced to said antennas, said means including means for producing signals proportional to the tangent and cotangent of the phase angle difference.

5. In the system of claim 4, means comprising the amplitude of said tangent and cotangent signals with reference signals to produce still further lower order digits in the code.

6. In a digital direction finding system employing a pair of spaced apart antennas, means deriving a pair of signals proportional to the sine and cosine of the phase angle displacement between antenna signals, logic means for processing said signals to produce a miltidigit code including means for comparing the absolute amplitudes of the sine and cosine signals and responsive to the smaller of the signals to compare the smaller signal with a preset fixed amplitude reference to produce a lower order digit of the code.

7. In the system of claim 6, means responsive to the sine and cosine signal to derive a signal proportional to the tangent, and means for comparing the tangent to a fixed amplitude signal to derive an additional digit.