FREKVENSSTYRBAR KVARTSOSKILLATOR MED STORT DRAGOMRAODE

摘要

1. A frequency-controllable quartz crystal oscillator in the form of a three-terminal network utilising combined capacitive-inductive pulling, comprising a first series circuit combination of a varactor diode (D), a first inductance (L1), and a quartz crystal (Q), which combination is connected in parallel with a second series circuit combination consisting of two capacitors (C1, C2) a first one of which is bridget by a first resistor (R1), a first connection point of the two series circuit combinations being connected to the base electrode of a first transistor (T1) whose emitter electrode is directly connected via a fifth resistor (R5) to a first operating voltage supply terminal (-U) and to the junction of the two capacitors (C1, C2) via a feedback arrangement, the other connection point of the two series circuit combinations being connected to a second operating voltage supply terminal, the collector electrode of the first transistor (T1) being connected to an output terminal (A) and via a fourth resistor (R4) to the second operating voltage supply terminal, and the varactor diode (D) being connected to a control voltage, characterized in that, the quartz crystal (Q) consists of a fundamental crystal, that the first series circuit combination contains a third resistor (R3) connected between the quartz crystal (Q) and the transistor end connection point of the two series circuit combinations, that the emitter electrode of the first transistor (T1) is connected via a diode (T2) to the junction point of the two capacitors (C1, C2), that the second capacitor (C2) is bridged by a second resistor (R2), that the first terminal of the varactor diode (D) is the terminal of the first series circuit combination connected to the second reference voltage supply source, and that the other terminal of the varactor diode (D) is connected via the first inductance (L1) to the quartz crystal (Q) via a sixth resistor (R6) to the control voltage supply (E).