Voltage controlled oscillator small in reduction of inductance and Q
View Patent ↗The voltage controlled oscillator contains a circuit board having a laminate of a plurality of insulating plates, a wiring pattern formed on a surface of the circuit board, an electronic part mounted on the surface of the circuit board, a resonance strip line provided on an inner layer of the circuit board, and a ground pattern formed on an inner layer of the circuit board which is disposed between the wiring pattern and the strip line. Further, a conductor-deleted portion of the ground pattern faces the vicinity including a portion having a high current density in the strip line. Thus, reductions of inductance and Q are small. In addition, a portion of the strip line is shielded by means of the ground pattern with respect to the wiring pattern.
1. A voltage controlled oscillator comprising:
a circuit board having a laminate of a plurality of insulating plates;
a wiring pattern formed on a surface of the circuit board;
an electronic part mounted on a surface of the circuit board;
a resonance strip line provided on an inner layer of the circuit board; and
a ground pattern formed on an inner layer of the circuit board which is disposed between the wiring pattern and the strip line,
wherein a conductor-deleted portion is provided in the ground pattern, and
the ground pattern faces the strip line in a state in which the conductor-deleted portion faces the vicinity including a portion having a high current density in the strip line, and
wherein the conductor-deleted portion faces the strip line in a range of 50 percent to 80 percent of a surface area of the strip line.
2. The voltage controlled oscillator according to claim 1 ,
wherein the strip line includes a pair of conductors arranged to face each other and spaced at a predetermined gap from each other, connection portions respectively provided at first ends of the pair of conductors, and a connecting conductor for connecting second ends of the pair of conductors to each other, and
the strip line has a U shape.
3. The voltage controlled oscillator according to claim 1 ,
wherein a cut groove for frequency adjustment is formed in the portion having the high current density in the strip line.
4. The voltage controlled oscillator according to claim 3 ,
wherein the cut groove is formed in a range of the conductor-deleted portion.
5. The voltage controlled oscillator according to claim 2 ,
wherein a band-shaped protruding conductor which protrudes from a side of the connecting conductor opposite to the connection portions is provided in the connecting conductor of the strip line.
6. The voltage controlled oscillator according to claim 5 ,
wherein by cutting a portion of the connecting conductor having a high current density in the strip line in a widthwise direction of the connecting conductor, a cut groove for frequency adjustment is provided to reach a protruding conductor.
7. The voltage controlled oscillator according to claim 6 ,
wherein the cut groove is formed in a range of the conductor-deleted portion.
8. The voltage controlled oscillator according to claim 1 ,
wherein the wiring pattern which is arranged at a position facing the conductor-deleted portion is formed with at least one of a ground wiring pattern and a direct current (DC) wiring pattern.