Patent
Dual loop receiver tuning and frequency tracking system
TLDR
In this paper, a first servo loop responsive to the beat frequency produced in a receiver automatically tunes an oscillator coupled to the input circuit of the receiver to the receiver frequency, while the oscillator automatically tracks this tuning.Abstract:
A first servo loop responsive to the beat frequency produced in a receiver automatically tunes an oscillator coupled to the input circuit of the receiver to the receiver frequency. A second servo loop then tunes the receiver to desired frequencies within the receiver band, while the oscillator automatically tracks this tuning. The second loop may include a comparator for comparing voltages indicative of the frequencies to which it is desired to tune the receiver with a voltage employed for tuning the oscillator.read more
Citations
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Method for tuning a filter circuit
TL;DR: In this article, a constant amplitude signal is applied to the trap circuit in a progression of successively different frequency increments, and the frequency increments cover a frequency range including the desired frequency.
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Automatic alignment system for a digital modem
TL;DR: In this paper, an automatic alignment system for use in a digital modem, having a performance indicator circuit associated therewith, adjusts the control voltages applied to selected alignment points therein in order to minimize the error indication output of the performance indicator.
Patent
Receiver including means selecting interference free channels
TL;DR: In this paper, the authors describe a device enabling the choice of a free channel, in a frequency range, which is available to a network of mobile subscribers greater in number than the channels, and if need be, according to a second characteristic having a lower quality level than the preceding one if no very good quality channel has been found.
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Low latency analog QAM coherent demodulation algorithm
TL;DR: In this article, a phase-locked loop is used to generate a local carrier signal for a quadrature amplitude modulated signal using a feedback signal derived from one or more demodulated signals of interest.
References
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Patent
Radio receiver alignment system
TL;DR: In this paper, a method and means for pre-tuning (or aligning) a crystal-controlled receiver to its proper operating frequency was proposed, which relates broadly to fixed-frequency radio receivers.
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