Composite resonance circuit and oscillation circuit using the circuit
OwnerKoichi Hiramainventor
Life of this patent
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Abstract
There is provided a resonance circuit using piezoelectric vibrator such as a quartz resonator, a coil, a capacitor, or an element equivalent to them in combination. When two resonance circuits having different resonance frequencies are combined, it is possible to configure an oscillation circuit and a filter capable of freely adjusting the frequency characteristic by utilizing the phenomenon that by changing the excitation current or voltage of the respective resonance circuits independently from each other, antiresonance frequency of the entire composite resonance circuit can be changed.
Claims28
A complex resonance circuit having an antiresonance characteristic variable with an electric power which is supplied across an input terminal and an output terminal, comprising:
- at least two resonant elements respectively having resonance frequencies different from each other;
- and
- an electric power supply circuit for dividing said electric power into two parts so as to respectively supply them to said resonant elements at a continuously varying distribution ratio, wherein
- said electric power supply circuit includes electric current paths, each having one end connected to a reference electric potential and including each of said resonant elements, and
- said electric power supply circuit respectively supplies said two parts to the other ends of said electric current paths and relays both of variations in electrical potentials at the other ends of said electric current paths to said output terminal.
An oscillation circuit comprising:
- an amplifier;
- and
- a feedback part for forming a feedback path connected from an output end of said amplifier to an input end of said amplifier,
- wherein
- said feedback part has a positive feedback path connected from said output end to said input end and a negative feedback path connected from said output end to said input end,
- said negative feedback path which is independent of said positive feedback path has at least two resonant elements respectively having different resonance frequencies and an electric power supply circuit for dividing an electric power supplied from said input end into two parts so as to respectively supply them to said resonant elements at a continuously varying division ratio,
- said electric power supply circuit includes two electric power supplying paths respectively connected to said two resonant elements and two variable attenuators or two variable gain amplifiers which are respectively positioned within said two electric power supplying paths, and
- each of said two electric power supplying paths includes a first electric current branch path connected from an output end of said amplifier to an input end and a second electric current branch path including said resonant element between a midpoint of said first electric current branch path and an earth potential.
Dependencies are inferred from the claim text.