High-stability phase-locked receiving system of the double phase-locked circuit.
In the cases of the conventional types of receivers designed for the highly accurate measurement of phase by receiving standard radio waves or waves for a radio navigation aid system, it has been customary to depend on the phase-lock receiving method using only one VCO (Voltage Controlled Oscillator) ; however, the receivers depending on this method are known to have some common shortcomings that are inescapable theoretically. In other words, in the conventional type of receiver, the received wave tends to become unstable, especially after the reception has been interrupted by some cause. In the phase-locked receiving method introduced here, two phase-locked oscillators (one for a high-sensitivity VCO used in the conventional receiver and the other for a high-stability VCO of low control sensitivity) are used so that, even when the receiving conditions are poor, the performance of the receiver can be kept stable, because the Doppler frequency of the received wave can be corrected for automatically by the second VCO depending on the velocity of motion of the receiver, without adverse effect on the high-speed tracking ability of the receiver. The principle of this phase-locked receiving method has been applied to the conventional Loran-C automatic tracking receiver as a means for improving its capability. Its accuracy and stability have been improved to almost five times those of the conventional receiver.
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| Format: | Journal Contribution biblioteca |
| Language: | Japanese |
| Published: |
1980
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| Online Access: | http://hdl.handle.net/1834/16259 |
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