Apparatus and method for finding a signal emission source
First Claim
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1. A method for sensing the direction of a source of emf emissions including a monotone signal, comprising the steps of:
- receiving the monotone signal with an omnidirectional antenna;
moving the antenna relative to the source of emissions and in a known direction while the emissions including the monotone signal are being received;
detecting the amount of phase change of the received monotone signal due to the moving of the antenna; and
generating an output signal indicative of the amount of phase change detected as an indication of the relationship between the known direction of movement and the direction of the source of emissions.
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Abstract
An apparatus and method are described for direction finding the source of emf emissions including a monotone signal by detecting the phase changes of the monotone signal during movement relative to the source. A software embodiment measures the amount of phase change.
136 Citations
20 Claims
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1. A method for sensing the direction of a source of emf emissions including a monotone signal, comprising the steps of:
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receiving the monotone signal with an omnidirectional antenna; moving the antenna relative to the source of emissions and in a known direction while the emissions including the monotone signal are being received; detecting the amount of phase change of the received monotone signal due to the moving of the antenna; and generating an output signal indicative of the amount of phase change detected as an indication of the relationship between the known direction of movement and the direction of the source of emissions. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. An apparatus for sensing the direction of a source of emf emissions including a monotone signal, comprising:
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means for receiving the monotone signal including an omnidirectional antenna being adapted to allow movement of the antenna relative to the source of emissions and in a known direction while the emissions including the monotone signal are being received; means for detecting an amount of phase change for the received monotone signal due to movement of the antenna relative to the source of emissions; and means for generating an output signal indicative of the amount of phase change detected as an indication of a relationship between the known direction of movement and the direction of the source of emissions. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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17. A method for calculating an amount of phase change of a received emf emission including a monotone signal, comprising the steps of:
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measuring frequency of the monotone signal; generating a reference signal in response to the measured frequency; modulating the received monotone signal with the reference signal and a quadrature version of the reference signal to produce I and Q components of the monotone signal; producing sequential, corresponding pairs of I and Q component values from the I and Q components; multiplying each pair of I and Q component values by the Q and I component values, respectively, of a subsequent I and Q component value pair to produce sequential pairs of corresponding cross products; and determining sign and magnitude differences between each pair of cross products as the amount of phase change of the monotone signal. - View Dependent Claims (18, 19, 20)
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Specification