Frequenzsynthetisierer für einen Generator zur Erzeugung von Signalen hoher Reinheit sowie dazugehörige Schaltungselemente wie VCO, PLL und Signalgenerator

摘要

The voltage controlled oscillator includes a resonant circuit (301) having at least a coil (L1) and a first variable capacitance diode (D1), and resonating within set variable frequency ranges. An active circuit (303) has an active element (T1) connected between its input and output, with the input being connected to the resonant circuit. A variable capacitance ratio device (304) has a second variable capacitance diode (D4) and one or more capacitors (C7,C8), connected in positive feedback loop between the active circuit input and output. The variable capacitance oscillates the active element at the resonant frequency of the resonant circuit. A variable controller changes the resonant frequency to apply a control voltage to the capacitance diodes (D1,D4) and to control the capacitance ratio between either capacitor (C7,C8) and the second variable capacitance (D4). The active element oscillation frequency is linearly adjustable over a wide bandwidth of more than one octa-chord w.r.t. the control voltage variation.