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US 3,946,395 AGranted
Radio direction finding apparatus
OwnerC. Edward Kirchhoffinventor
Life of this patent
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OwnerC. Edward Kirchhoffinventor
Estimating the term…
A circle arc array of element antennas is capable of receiving at all times radio signals from a source located anywhere in a wide angle or complete circle of azimuth directions, the direction of arrival of a received signal being indicated by radio receiving equipment. The source signal received by each element antenna is directed into two or three channels having different phase delays. The output signals from the first channels of all of the element antennas are combined and connected to a first radio receiver, the phase delays in the first channels being equal for all of the element antennas. The output signals from the second channels of all of the element antennas are combined and connected to the input of a second receiver, the phase delays in the second channels all being different from each other in a uniform phase progression. The phase progression corresponds to a clockwise azimuthal progression of the associated element antennas. The phase difference between the signals of the first and second radio receivers indicates the azimuth direction from which the source radio wave is arriving at the antenna array. If desired, counterclockwise-phased output signals from third channels of all of the element antennas may be employed for a redundant indication of azimuth direction of arrival, to reduce errors. Antenna elements may be arranged in the same circular arc array fashion, with the plane of the elements being vertical, in order to measure elevation direction of arrival.
In a radio direction finding apparatus comprising a plurality of spaced apart element antennas for receiving a radiated microwave signal from a source whose direction is to be determined, the radiated signal establishing phase displaced antenna element signals in element antennas of said array with the phase relationship of the signals depending upon the direction of the source, first means for combining said phase displaced antenna element signals to provide first and second resultant signals in the microwave range whose relative phases indicate the direction of said source and means for down-converting said resultant signals to an intermediate frequency signal and for measuring the phase difference therebetween, said first means comprising a quadrature coupler matrix for combining said antenna element signals at the frequency of received radiation for providing said first and second resultant signals.
Radio direction finding apparatus comprising a planar array of spaced apart element antennas for receiving a radiated signal from a source whose direction is to be determined, the radiated signal establishing phase displaced antenna element signals in element antennas of said array with the phase relationship of the signals depending upon the direction of the source, combining means for combining said element signals in a first predetermined phase relationship in which any phase shift introduced into said element signals is equal for all element signals to produce a first resultant signal, additional means for phase shifting the element signals by different amounts with the phase shift changing progressively in a predetermined order of said antenna elements and combining said signals to provide a second resultant signal whose phase with respect to said first resultant signal differs for different directions of the source, and means for measuring the phase difference between said first and second resultant signals to indicate a direction coordinate in the plane of the array for the source, whereby the phase of said first resultant signal is substantially independent of the direction of the source.
Radio direction finding apparatus comprising a planar array of spaced-apart element antennas each for receiving a respective element signal from the same radiation source, first means for combining the element signals with equal phase shifts to produce a first resultant signal whose phase is substantially independent of direction of the source, means for phase-shifting the element signals by different amounts for different element antennas, second means for combining the phase-shifted element signals to produce a second resultant signal whose phase is different for different directions of the source, and means for measuring the phase difference between said first and second resultant signals to indicate a coordinate of direction of the radiation source, said coordinate being in the plane of the array.
Radio direction finding apparatus as defined in clsim 5 and wherein each of said element antennas has a radiation pattern whose principal lobe is narrower than 100.degree. between halfpower points.
Radio direction finding apparatus comprising a plurality of element antennas arrayed at equal angular intervals in a circle for receiving signals from a radio source;
A method of radio direction finding comprising the steps of providing a planar array of element antennas spaced apart symmetrically over a span of directions, each element antenna receiving an element signal from the same radiation source;
In a radio direction finding apparatus comprising a plurality of spaced apart element antennas for receiving a radiated signal from a source whose direction is to be determined, the radiated signal establishing phase displaced antenna element signals in element antennas of said array with the phase relationship of the signals depending upon the direction of the source, first means for combining said phase displaced antenna element signals to provide first and second resultant signals whose relative phases indicate the direction of said source, and means for measuring the phase difference therebetween, said first means comprising a quadrature coupler matrix for combining said antenna element signals at the frequency of received radiation for providing said first and second resultant signals.
Dependencies are inferred from the claim text.