Quartz-crystal microwave oscillator of the common-emitter transmission type with two transistors and a predetermined loaded Q factor
First Claim
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1. A quartz-crystal microwave oscillator which is capable of operating at frequencies within the range of 750 to 1500 MHz and the feedback loop of which satisfies the Barkhausen conditions, wherein:
- the feedback loop includes at least the following elements placed in series and in this order;
a first matching quadripole, a first amplifying stage, a second matching quadripole, a resonator, a third matching quadripole, a second amplifying stage, a fourth matching quadripole and a power divider;
the amplifying stages each have one transistor mounted with a common emitter connection;
the matching quadripoles make it possible to match the input and output impedances of the amplifying stage with the other elements of the feedback loop;
the resonator is constituted mainly by a quartz crystal;
the power divider serves to collect the output signal of the oscillator for onward transmission to a utilization circuit.
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Abstract
The resonant frequency of a quartz-crystal microwave oscillator is the fundamental frequency in the partial mode of the crystal and makes it possible to maintain the loaded Q of the resonator at a high value. This microwave oscillator is provided with two amplifying stages and has a signal-to-noise ratio of the order of 160 dB.
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10 Claims
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1. A quartz-crystal microwave oscillator which is capable of operating at frequencies within the range of 750 to 1500 MHz and the feedback loop of which satisfies the Barkhausen conditions, wherein:
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the feedback loop includes at least the following elements placed in series and in this order;
a first matching quadripole, a first amplifying stage, a second matching quadripole, a resonator, a third matching quadripole, a second amplifying stage, a fourth matching quadripole and a power divider;the amplifying stages each have one transistor mounted with a common emitter connection; the matching quadripoles make it possible to match the input and output impedances of the amplifying stage with the other elements of the feedback loop; the resonator is constituted mainly by a quartz crystal; the power divider serves to collect the output signal of the oscillator for onward transmission to a utilization circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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