Oscillator circuit

Patent metadata

Field	Value
Publication number	US-9240755-B2
Application number	US-201414252783-A
Country	US
Kind code	B2
Filing date	Apr 15, 2014
Priority date	Apr 17, 2013
Publication date	Jan 19, 2016
Grant date	Jan 19, 2016

Abstract

An oscillator circuit includes a first resonator, a second resonator, and a frequency adjusting unit. The second resonator has a frequency characteristic different from a frequency characteristic of the first resonator. The frequency adjusting unit is configured to change a ratio between a contribution of the first resonator and a contribution of the second resonator so as to adjust an output frequency.

First claim

What is claimed is:

1. An oscillator circuit, comprising:
a first resonator;
a second resonator, having a frequency characteristic different from a frequency characteristic of the first resonator;
a frequency adjusting unit, being configured to change a ratio between a contribution of the first resonator and a contribution of the second resonator so as to adjust an output frequency,
wherein the frequency characteristic is a resonance frequency,
the frequency adjusting unit includes:
a first adjusting unit, being configured to adjust a first current value of a first current, the first current flows through a first path, the first path is connected to the first resonator;
a second adjusting unit, being configured to adjust a second current value of a second current, the second current flows through a second path, the second path is connected to the second resonator;
a converting unit, being configured to convert the first current and the second current into a voltage corresponding to the first current value and the second current value; and
an amplifying unit, being configured to amplify a voltage converted by the converting unit and apply the amplified voltage to the first resonator and the second resonator;

wherein the first adjusting unit includes a first transistor and a first variable resistor, the first transistor causing a flow of the first current, the first variable resistor being configured to adjust the first current value, and
the second adjusting unit includes a second transistor and a second variable resistor, the second transistor causing a flow of the second current, the second variable resistor being configured to adjust the second current value.

2. The oscillator circuit according to claim 1 , wherein
the frequency adjusting unit includes: a ratio adjusting unit,
the ratio adjusting unit is configured to adjust a ratio between the first current value and the second current value.

3. The oscillator circuit according to claim 2 , wherein
the first resonator connects in series to the first adjusting unit in the first path between the amplifying unit and the first adjusting unit,
the second resonator connects in series to the second adjusting unit in the second path between the amplifying unit and the second adjusting unit, and
an anti-resonance frequency of the first resonator and an anti-resonance frequency of the second resonator are higher than a resonance frequency of the first resonator and a resonance frequency of the second resonator.

4. The oscillator circuit according to claim 1 , wherein
the first resonator connects in series to the first adjusting unit in the first path between the amplifying unit and the first adjusting unit,
the second resonator connects in series to the second adjusting unit in the second path between the amplifying unit and the second adjusting unit, and
an anti-resonance frequency of the first resonator and an anti-resonance frequency of the second resonator are higher than a resonance frequency of the first resonator and a resonance frequency of the second resonator.

5. The oscillator circuit according to claim 1 , wherein
the first resonator connects in series to the first adjusting unit in the first path between the amplifying unit and the first adjusting unit,
the second resonator connects to the second path and a ground, the second path being disposed between the amplifying unit and the second adjusting unit, and
an anti-resonance frequency of the first resonator and a resonance frequency of the second resonator are frequencies between a resonance frequency of the first resonator and an anti-resonance frequency of the second resonator.

6. The oscillator circuit according to claim 2 , wherein
the first resonator connects in series to the first adjusting unit in the first path between the amplifying unit and the first adjusting unit,
the second resonator connects to the second path and a ground, the second path being disposed between the amplifying unit and the second adjusting unit, and
an anti-resonance frequency of the first resonator and a resonance frequency of the second resonator are frequencies between a resonance frequency of the first resonator and an anti-resonance frequency of the second resonator.

7. An oscillator circuit, comprising:
a first resonator;
a second resonator, having a frequency characteristic different from a frequency characteristic of the first resonator;
a frequency adjusting unit, being configured to change a ratio between a contribution of the first resonator and a contribution of the second resonator so as to adjust an output frequency,
wherein the frequency characteristic is a resonance frequency,
the frequency adjusting unit includes:
a first adjusting unit, being configured to adjust a first current value of a first current, the first current flows through a first path, the first path is connected to the first resonator;
a second adjusting unit, being configured to adjust a second current value of a second current, the second current flows through a second path, the second path is connected to the second resonator;
a converting unit, being configured to convert the first current and the second current into a voltage corresponding to the first current value and the second current value; and
an amplifying unit, being configured to amplify a voltage converted by the converting unit and apply the amplified voltage to the first resonator and the second resonator;

wherein the first resonator connects in series to the first adjusting unit in the first path between the amplifying unit and the first adjusting unit,
the second resonator connects in series to the second adjusting unit in the second path between the amplifying unit and the second adjusting unit, and
an anti-resonance frequency of the first resonator and an anti-resonance frequency of the second resonator are higher than a resonance frequency of the first resonator and a resonance frequency of the second resonator.

8. An oscillator circuit, comprising:
a first resonator;
a second resonator, having a frequency characteristic different from a frequency characteristic of the first resonator;
a frequency adjusting unit, being configured to change a ratio between a contribution of the first resonator and a contribution of the second resonator so as to adjust an output frequency,
wherein the frequency characteristic is an anti-resonance frequency,
the frequency adjusting unit includes:
a first amplifier, being configured to amplify a signal to be input;
a second amplifier, being configured to inversely amplify an output signal of the first amplifier and input the inversely amplified output signal to the first amplifier;
a resistor, being connected between an input and an output of the second amplifier;
a third amplifier, being connected in series to the first resonator and connected in parallel to the resistor; and
a fourth amplifier, being connected in series to the second resonator and connected in parallel to the resistor, wherein

at least one of the third amplifier and the fourth amplifier has a variable gain.

9. The oscillator circuit according to claim 8 , wherein
the first resonator has a resonance frequency smaller than a resonance frequency of the second resonator, and
the first resonator has an anti-resonance frequency larger than the resonance frequency of the second resonator.

10. The oscillator circuit according to claim 8 , wherein
the first resonator has a resonance frequency smaller than a resonance frequency of the second resonator, and
the frequency adjusting unit includes a first negative capacitance circuit disposed in parallel to the first resonator, the first negative capacitance circu

Assignees

• Nihon Dempa Kogyo Co

Inventors

• Hirose Masaki
• Akazawa Yukio
• Hamaguchi Hiroki
• Ishii Takehito
• Kimura Noritoshi

Classifications

• H03B2201/02

  Varying the frequency of the oscillations by electronic means · CPC title

• H03B5/366

  and comprising means for varying the frequency by a variable voltage or current · CPC title

• H03B21/01 Primary

  by beating unmodulated signals of different frequencies · CPC title