Phase-controlled high frequency oscillator

Claim 1

In a phase-controlled high frequency oscillator having a voltage-controlled oscillator which generates an oscillator frequency, a reference frequency generator, a phase comparison circuit for comparing the phase of the oscillator frequency to the phase of the reference frequency, a pair of direct current sources controlled by said phase comparison circuit for generating charge pulses proportional to the phase difference determined by said phase comparison circuit which are supplied to a charging capacitor connected to said voltage controlled oscillator for supplying a control voltage thereto, whereby in the steady-state condition of the control loop both current sources generate charge pulses of equal size and opposite polarity having a duration which is substantially less than the period of said reference frequency, the improvement of: an auxiliary circuit interconnected between said pair of current sources and said charging capacitor for generating a correction current proportional to the integral of the difference between the charge pulses generated by the current sources, said auxiliary circuit consisting of at least one circuit element connected to both of said current sources, a voltage drop being generated across said element corresponding to the charge pulses from said current sources, an integrating capacitor connected to said circuit element, at least one first rectifier interconnected between each of said current sources and said integrating capacitor such that said integrating capacitor is charged with said voltage drop, and an impedance transformer connected to said integrating capacitor for generating said correction current from the voltage across said integrating capacitor, whereby said auxiliary circuit generates said correction current only when said pulses from said current sources are charge pulses having a period which is less than the period of said reference frequency.