Radio direction finder
First Claim
1. A radio direction finder for determining the bearing of received radio wave, comprising:
- a nondirectional antenna having an output;
a plurality of directional antennas having a directivity and respective outputs;
an oscillator means for producing AC signals, each having a phase angle corresponding to the configuration of each of said directional antennas and including reference oscillator means for producing output pulses, reference counter means for counting said output pulses from said reference oscillator means to produce count outputs, and flip-flop means for receiving the count outputs of said reference count means, said flip-flop means being responsive to said count outputs of said modulator means for causing said modulator means to modulate the respective outputs of said directional antennas in accordance therewith;
modulator means for modulating the respective outputs of said directional antennas with said respective AC signals to derive respective modulation outputs;
phase-shifting means for phase-shifting the output of said nondirectional antenna to produce a phase-shifted output thereof;
additive means for superimposing the respective modulation outputs of said modulator means on said phase-shifted output of said nondirectional antenna to develop a synthesized output;
receiving circuit means for demodulating said synthesized output of said synthesizing means to recover said AC signals, and producing an output having a phase;
tracking circuit means for automatically tracking the phase of the output of said receiving circuit means so as to derive the bearing of the received radio wave; and
display means for displaying the bearing of the received radio wave numerically.
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Accused Products
Abstract
A radio direction finder, designed to determine the direction of arrival of radio waves utilizing a nondirectional antenna and a plurality of directional antennas having respective directivities, comprises an oscillator for producing A.C. signals having a phase angle in correspondence to the configuration of each of the directional antennas, modulators for modulating the respective outputs of the directional antennas with respective A.C. signals, a additive circuit for superimposing the respective modulation outputs on the phase-shifted output of the nondirectional antenna, and a receiving circuit for demodulating the added output of the additive circuit to recover the A.C. signals. The radio direction finder is further characterized by an automatic phase tracking counter for following the phase of the output of the receiving circuit, and a display unit for displaying the bearing of the received radio wave numerically. Special circuitry is provided for achieving accelerated automatic phase tracking, for stopping the automatic phase tracking procedure upon the occurrence of certain disturbances, and for restarting the procedure upon disappearance of the disturbances.
10 Citations
7 Claims
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1. A radio direction finder for determining the bearing of received radio wave, comprising:
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a nondirectional antenna having an output; a plurality of directional antennas having a directivity and respective outputs; an oscillator means for producing AC signals, each having a phase angle corresponding to the configuration of each of said directional antennas and including reference oscillator means for producing output pulses, reference counter means for counting said output pulses from said reference oscillator means to produce count outputs, and flip-flop means for receiving the count outputs of said reference count means, said flip-flop means being responsive to said count outputs of said modulator means for causing said modulator means to modulate the respective outputs of said directional antennas in accordance therewith; modulator means for modulating the respective outputs of said directional antennas with said respective AC signals to derive respective modulation outputs; phase-shifting means for phase-shifting the output of said nondirectional antenna to produce a phase-shifted output thereof; additive means for superimposing the respective modulation outputs of said modulator means on said phase-shifted output of said nondirectional antenna to develop a synthesized output; receiving circuit means for demodulating said synthesized output of said synthesizing means to recover said AC signals, and producing an output having a phase; tracking circuit means for automatically tracking the phase of the output of said receiving circuit means so as to derive the bearing of the received radio wave; and display means for displaying the bearing of the received radio wave numerically. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification