Voltage-controlled oscillation circuit

Abstract:

A voltage-controlled oscillation (VCO) circuit includes a current generator, a variable capacitor having a capacitance value which changes in accordance with a tuning voltage, an inductor which is electrically connected to the variable capacitor in parallel, and a fixed, capacitor which is electrically connected to the variable capacitor in parallel. The variable capacitor is electrically connected to the current generator in series.

Citations

4918406 5920235 6097258 6225871 6411171 6556093

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Claims:

What is claimed is:

1. A voltage-controlled oscillation (VCO) circuit, comprising: a current generator; a variable capacitor having a capacitance value which changes in accordance with a tuningvoltage, and which is electrically connected to the current generator in series; an inductor which is electrically connected to the variable capacitor in parallel; and a fixed capacitor which is electrically connected to the variable capacitor inparallel, and which has a set capacitance, wherein the VCO circuit has first, second and third metal layers, wherein the fixed capacitor includes a lower electrode which is formed as the first metal layer and an upper electrode which is formed as thesecond metal layer, and wherein the inductor is electrically connected to the variable capacitor by a pair of wiring layers which are formed as the third metal layer.

2. The VCO circuit according to claim 1, wherein the upper electrode is electrically connected to one of the pair of wiring layers and the lower electrode is electrically connected to an other one of the pair of wiring layers, through aplurality of through holes.

3. The VCO circuit according to claim 1, wherein the upper and lower electrodes are a polycrystalline semiconductor material.

4. The VCO circuit according to claim 3, wherein the upper electrode is electrically connected to one of the pair of wiring layers and the lower electrode is electrically connected to an other one of the pair of wiring layers, through aplurality of through holes.

5. The VCO circuit according to claim 1, wherein the upper and lower electrodes are a noncrystalline semiconductor material.

6. The VCO circuit according to claim 5, wherein the upper electrode is electrically connected to one of the pair of wiring layers and the lower electrode is electrically connected to an other one of the pair of wiring layers, through aplurality of through holes.

7. A voltage-controlled oscillation (VCO) circuit, comprising: a current generator; a variable capacitor having a capacitance value which changes in accordance with a tuning voltage, and which is electrically connected to the current generatorin series; an inductor which is electrically connected to the variable capacitor in parallel; and a fixed capacitor which is electrically connected to the variable capacitor in parallel, and which has a set capacitance, wherein the VCO circuit hasfirst, second and third metal layers, wherein the fixed capacitor includes a lower electrode which is formed as the first metal layer and an upper electrode, and wherein the inductor is electrically connected to the variable capacitor by a pair of wiringlayers which are formed as the second metal layer.

8. The VCO circuit according to claim 7, wherein the upper electrode is electrically connected to one of the pair of wiring layers through a metal connector, and the lower electrode is electrically connected to an other one of the pair of wiringlayers through a plurality of through holes.

9. The VCO circuit according to claim 8, wherein the fixed capacitor is located between the pair of wiring layers.

10. The VCO circuit according to claim 7, wherein the upper and lower electrodes are a polycrystalline semiconductor material.

11. The VCO circuit according to claim 10, wherein the upper electrode is electrically connected to one of the pair of wiring layers and the lower electrode is electrically connected to an other one of the pair of wiring layers, through aplurality of through holes.

12. The VCO circuit according to claim 7, wherein the upper and lower electrodes are a noncrystalline semiconductor material.

13. The VCO circuit according to claim 12, wherein the upper electrode is electrically connected to one of the pair of wiring layers and the lower electrode is electrically connected to an other one of the pair of wiring layers, through aplurality of through holes.

14. A voltage-controlled oscillation (VCO) circuit, comprising: a current generator; a variable capacitor having a capacitance value which changes in accordance with a tuning voltage, and which is electrically connected to the current generatorin series; an inductor which is electrically connected to the variable capacitor in parallel; and an even number of fixed capacitors which are electrically connected to the variable capacitor in parallel, the fixed capacitors having a same structureand a same capacitance, wherein the VCO circuit has first, second and third metal layers, wherein the fixed capacitors respectively include a lower electrode which is formed as the first metal layer and an upper electrode which is formed as the secondmetal layer, and wherein the inductor is electrically connected to the variable capacitor by a pair of wiring layers which are formed as the third metal layer.

15. The VCO circuit according to claim 14, wherein the upper electrodes are electrically connected to one of the pair of wiring layers and the lower electrodes are electrically connected to an other one of the pair of wiring layers, through aplurality of through holes.

16. The VCO circuit according to claim 14, wherein the upper and lower electrodes are a polycrystalline semiconductor material.

17. The VCO circuit according to claim 16, wherein the upper electrodes are electrically connected to one of the pair of wiring layers and the lower electrodes are electrically connected to an other one of the pair of wiring layers, through aplurality of through holes.

18. The VCO circuit according to claim 14, wherein the upper and lower electrodes are a noncrystalline semiconductor material.

19. The VCO circuit according to claim 18, wherein the upper electrodes are electrically connected to one of the pair of wiring layers and the lower electrodes are electrically connected to an other one of the pair of wiring layers, through aplurality of through holes.

20. The VCO circuit according to claim 14, wherein the upper electrodes are electrically connected to one of the pair of wiring layers through a metal connector, and the lower electrodes are electrically connected to an other one of the pair ofwiring layers through a plurality of through holes.

21. A voltage-controlled oscillation (VCO) circuit, comprising: a current generator; a variable capacitor having a capacitance value which changes in accordance with a tuning voltage, and which is electrically connected to the current generatorin series; an inductor which is electrically connected to the variable capacitor in parallel; and an even number of fixed capacitors which are electrically connected to the variable capacitor in parallel, the fixed capacitors having a same structureand a same capacitance, wherein the VCO circuit has first, second and third metal layers, wherein the fixed capacitors respectively include a lower electrode which is formed as the first metal layer and an upper electrode, and wherein the inductor iselectrically connected to the variable capacitor by a pair of wiring layers which are formed as the second metal layer.

22. The VCO circuit according to claim 21, wherein the upper electrodes are electrically connected to one of the pair of wiring layers through a metal connector, and the lower electrodes are electrically connected to an other one of the pair ofwiring layers through a plurality of through holes.

23. The VCO circuit according to claim 21, wherein the upper electrodes are a metal and the lower electrodes are a polycrystalline semiconductor material.

24. The VCO circuit according to claim 23, wherein the upper electrodes are electrically connected to one of the pair of wiring layers and the lower electrodes are electrically connected to an other one of the pair of wiring layers, through aplurality of through holes.

25. The VCO circuit according to claim 21, wherein the upper electrodes are a metal and the lower electrodes are a noncrystalline semiconductor material.

26. The VCO circuit according to claim 25, wherein the upper electrodes are electrically connected to one of the pair of wiring layers and the lower electrodes are electrically connected to an other one of the pair of wiring layers, through aplurality of through holes.

27. A voltage-controlled oscillation (VCO) circuit, comprising: a current generator; a variable capacitor having a capacitance value which changes in accordance with a tuning voltage, and which is electrically connected to the current generatorin series; an inductor which is electrically connected to the variable capacitor in parallel; and an even number of fixed capacitors which are electrically connected to the variable capacitor in parallel, the fixed capacitors having a same structureand a same capacitance, wherein the VCO circuit has first and second metal layers, wherein the fixed capacitors respectively include a lower electrode which is formed as the first metal layer and an upper electrode, and wherein the inductor iselectrically connected to the variable capacitor by a pair of wiring layers which are formed as the second metal layer.

Patent number:
6720835
View patent at USPTO

Filing date:
August 6, 2002

Issue date:
April 13, 2004

Inventor:
Ken Fujita (Tokyo, JP)

Assignee:
Oki Electric Industry Co., Ltd. (Tokyo, JP)

Primary Examiner:
My-Trang Nu Ton

Attorney, Agent or Firm:
Volentine Francos, PLLC

Current U.S. Classification: 331/117R