摘要 |
A method is presented for minimizing the current consumption and the operating voltage of a voltage controlled oscillator. According to the invention the oscillator's (Q2) output signal (RFout) is detected as a DC voltage signal (Vgs) in a clamp/voltage multiplier circuit (U1, U2), preferably after a isolating amplifier (Q1). This detected signal is supplied in a feedback loop to a field effect transistor (FET1) controlling the oscillator's (Q2) current, whereby the field effect transistor controls the current (Ib) in the main current path to a predetermined minimum value. In this superimposed arrangement of the oscillator and the isolating amplifier the supply voltage (B) can be minimized by arranging, regarding the DC current, the isolating amplifier (Q1) in parallel with the field effect transistor (FET1) in the emitter branch of the oscillator (Q2). <IMAGE> |