
US Patent No: 4,457,006
Number of patents in Portfolio can not be more than 2000
Global positioning system receiver
Stats
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Jun 26, 1984
Issued date -
Nov 16, 1981
filing date -
06/321,945
serial no -
Expired
status
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Abstract
In a Global Positioning System type of navigation system, a biphase modulated radio frequency input signal is applied to the "front end" of a double heterodyne receiver having a second intermediate frequency stage which operates in the audio frequency range. The audio output signal is phase locked to a 1 KHz reference signal and is applied to a microprocessor for processing via an interface circuit which includes a relatively simple amplitude detector and a novel biphase detector. The microprocessor also controls the phase shifting of a pseudorandom noise code generator whose output is modulated with the output of the first intermediate frequency stage of the receiver.
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International Classification(s)
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Cited Art
| Patent Info | (Count) | # Cites | Year |
|---|---|---|---|
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| 4,198,604 Heterodyne phase lock system | 24 | 1977 | |
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| 2002/0114,513 Color image processing device and color image processing method | 1 | 2002 | |