Wide-band frequency-controlled crystal oscillator
AssigneeCompagnie d'Electronique et de Piezo-Electricite
InventorJacques Helle
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Abstract
An oscillator formed of an amplifier with a feedback loop containing two parallel connected crystals in series with a voltage variable capacitance. The two crystals have respective resonance frequencies above and below the limits of a wide band over which the oscillator frequency can be varied by a control voltage. Frequency versus control voltage linearity is improved by inductances inserted in parallel and in series, respectively, with the lower and higher frequency crystals.
Claims4
A wide-band frequency-controlled crystal oscillator, consisting, of an oscillating circuit in the form of a feedback loop, comprising an amplifier (A), a first element (C.sub.2) having variable reactance in dependence upon electrical quantities or signals, and a second element oscillating with a high Q-factor, wherein said second element is formed by two piezoelectric crystals (X.sub.1) (X.sub.2) connected in parallel through a connecting capacitor (C.sub.l), these two crystals having resonance frequencies respectively above the below those of said wide band.
Dependencies are inferred from the claim text.