Voltage controlled oscillator with phase control circuits
AssigneeTokyo Shibaura Electric Co., Ltd.
InventorHiroshi Gomi
Life of this patent
Estimating the term…
Abstract
A tank circuit including a quartz vibrator and a phase shifter connected to the tank circuit for forming a vector signal e.sub.1 from the tank circuit and a vector signal e.sub.2 delayed a predetermined angle from the signal e.sub.1. A differential circuit is used to subtract e.sub.1 from e.sub.2 thus forming a difference signal e.sub.3. The delayed signal e.sub.2 is inverted by a phase inverting circuit to obtain two signals e.sub.2 and -e.sub.2 which are applied to an addition circuit where their relative amplitude ratio is controlled. The addition circuit adds signal e.sub.3 to the signals e.sub.2 and e.sub.3 whose relative amplitude ratio has been controlled for producing a sum signal which is fed back to the tank circuit.
Claims7
A voltage controlled oscillator comprising:
- a resonant circuit;
- means for phase-shifting by a predetermined amount a first reference vector signal (e.sub.1) from one end of said resonant circuit, thereby generating a second reference vector signal (e.sub.2);
- means for generating a third vector signal (e.sub.3) equal to the difference between said first and said second reference vector signals (e.sub.1, e.sub.2);
- means for generating a vector signal e.sub.4 and for feeding back said vector signal and said third vector signal e.sub.3 to said resonant circuit, including means for generating a vector signal 180.degree. out of phase with said vector signal e.sub.4 and including a first control-addition means for receiving one of said first, second and third vector signals, for controlling the absolute value of said vector signal e.sub.4 relative to said vector signal 180.degree. out of phase with said vector signal and for combining both vector signals;
- and
- hue control signal generating means including means for generating a fourth vector signal -e.sub.3 that is 180.degree. out of phase with said third vector signal e.sub.3, and further including a first vector adding circuit for adding one of said third vector signal e.sub.3 and fourth vector signal (-e.sub.3) to a vector signal (-e.sub.2 or +e.sub.2) which differs in phase by +90.degree. from said third or fourth vector signals, and generating a fifth vector signal (e.sub.6) said hue control signal generating means further including a second vector adding circuit for adding one of said third vector signal (e.sub.3) and said fourth vector signal (-e.sub.3) to a vector signal (-e.sub.2 or +e.sub.2) which differs in phase by -90.degree. from said third or fourth vector signal, thereby generating a sixth vector signal (e.sub.5).
Dependencies are inferred from the claim text.