Voltage controlled oscillator with phase control circuits

摘要

A tank circuit including a quartz vibrator and a phase shifter connected to the tank circuit for forming a vector signal e1 from the tank circuit and a vector signal e2 delayed a predetermined angle from the signal e1. A differential circuit is used to subtract e1 from e2 thus forming a difference signal e3. The delayed signal e2 is inverted by a phase inverting circuit to obtain two signals e2 and -e2 which are applied to an addition circuit where their relative amplitude ratio is controlled. The addition cicuit adds signal e3 to the signals e2 and e3 whose relative amplitude ratio has been controlled for producing a sum signal which is fed back to the tank circuit.