Patent
Voltage controlled oscillators
TLDR
In this paper, a frequency synthesiser comprises a voltage controlled oscillator, VCO, having means for fine tuning the oscillator frequency and switchable capacitive elements for coarse tuning the frequency.Abstract:
A frequency synthesiser comprises a voltage controlled oscillator, VCO, having means for fine tuning the oscillator frequency and switchable capacitive elements for coarse tuning the oscillator frequency. First comparison means are provided for comparing the frequency and phase of the output of the VCO or a signal derived therefrom with that of a reference frequency signal to provide an error signal, the error signal being provided to said means for fine tuning the oscillator frequency. Second comparison means are provided for comparing the error signal against one or more reference values and a control means receives the result of the comparison from the second comparison means and switches said switchable capacitive elements on and off in dependence upon the result so as to coarse tune the oscillator frequency.read more
Citations
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TL;DR: In this paper, a control circuit is configured to select ones of the switches of the capacitor circuit and of the varactor circuit and to provide a selected control voltage to the varactors to apply a desired capacitance to the amplifier.
References
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Patent
Method and apparatus for providing coarse and fine tuning control for synthesizing high-frequency signals for wireless communications
TL;DR: In this paper, a method and apparatus for synthesizing high-frequency signals is disclosed that overcomes integration problem associated with prior implementations while meeting demanding phase noise and other impurity requirements.
Patent
Frequency synthesizer having microcomputer supplying analog and digital control signals to VCO
TL;DR: A frequency synthesizer as discussed by the authors is an oscillator which can be coarse-tuned by a first input receiving a digital signal for selecting one of a plurality of frequency ranges, and fine tuned by a second input receiving an analog signal for select the desired frequency within the selected frequency range.
Patent
Method and apparatus for fully integrating a voltage controlled oscillator on an integrated circuit
TL;DR: In this article, a method and apparatus for fully integrating a Voltage Controlled Oscillator (VCO) on an integrated circuit is described, which is implemented using a differential-mode circuit design.
Patent
Fuse-trimmed tank circuit for an integrated voltage-controlled oscillator
Robert Cox,Gwilym Luff +1 more
TL;DR: In this article, a fuse-trimmed tank circuit for an integrated voltage-controlled oscillator (VCO) is presented, which includes an L-C portion, a cross-coupled pair of transistors, whose collectors are coupled to the L-c portion, and a capacitor coupled across the emitters of the cross coupled pairs.
Patent
Voltage controlled oscillator
TL;DR: In this paper, the authors proposed a solution to provide a miniaturized voltage controlled oscillator (VCO) which can be stably oscillated, by generating a second control signal, for which the phase change component of an input control signal is corrected by changing a frequency, and positively feeding the second controller signal back to an oscillation means.