Crystal oscillator device, oscillation method and heater

• US 7,378,916 B2
• Filed: 02/14/2005
• Issued: 05/27/2008
• Est. Priority Date: 02/20/2004
• Status: Expired due to Fees

• Current Assignee: Nihon Dempa Kogyo Company Limited
• Original Assignee: Nihon Dempa Kogyo Company Limited
• Inventors: Nakamura, Akihiro, Ishikawa, Takaaki, Ono, Kozo, Fukuda, Minoru, Asamura, Fumio, Oita, Takeo
• Primary Examiner(s): Lee; Benny
• Assistant Examiner(s): Gannon; Levi
• Application Number:
  US11/057,453
• Publication Number:
  US 20050184819A1
• Time in Patent Office: 1,198 Days
• Field of Search: 331/158, 331/162, 331/60, 310/361
• US Class Current: 331/158
• CPC Class Codes: H03B 5/04 Modifications of generator to compensate for variations in physical values, e.g. power supply, load, temperature
• CPC Class Codes: H03B 5/366 and comprising means for varying the frequency by a variable voltage or current

Abstract

The crystal oscillator device for simultaneously generating oscillator signals with a plurality of oscillation modes of a crystal unit, comprising: a primary resonator unit filtering the oscillator signal with a primary oscillation mode, which is one of the oscillation modes, from the output of the crystal unit, a secondary resonator unit filtering the oscillation signal, bearing a different resonance frequency from that of the primary resonator unit, with the primary oscillation mode from the output of the crystal unit, a primary phase synthesis unit, synthesizing the phases of the output signal of the primary resonator unit and the output signal of the secondary resonator unit, a tertiary resonator unit, a quaternary resonator unit, and a secondary phase synthesis unit.

Claims

1. A crystal oscillator device for simultaneously generating oscillator signals with a plurality of oscillation modes of a crystal unit, comprising:

a primary resonator unit filtering the oscillator signal with a primary oscillation mode, which is one of the oscillation modes, from the output of the crystal unit;

a secondary resonator unit filtering the oscillation signal, bearing a different resonance frequency from that of the primary resonator unit, with the primary oscillation mode from the output of the crystal unit;

a primary phase synthesis unit, synthesizing the phases of the output signal of the primary resonator unit and the output signal of the secondary resonator unit;

a tertiary resonator unit filtering the oscillator signal with a secondary oscillation mode, which is one of the oscillation modes, from the output of the crystal unit;

a quaternary resonator unit filtering the oscillator signal, bearing a different resonance frequency from that of the tertiary resonator unit, with the secondary oscillation mode from the output of the crystal unit; and

a secondary phase synthesis unit, synthesizing the phases of the output signal of the tertiary resonator unit and the output signal of the quaternary resonator unit,

wherein the primary phase synthesis unit and the secondary phase synthesis unit are a differential amplifier.

2. The crystal oscillator device according to claim 1, wherein the primary resonator unit, the secondary resonator unit, the tertiary resonator unit and the quaternary resonator unit are crystal resonators.

3. The crystal oscillator device according to claim 1, wherein the primary resonator unit, the secondary resonator unit, the tertiary resonator unit and the quaternary resonator unit are directly connected to the crystal unit.

4. The crystal oscillator device according to claim 1, wherein the crystal unit is an SC-cut crystal unit or an IT-cut crystal unit, and the primary oscillation mode is a C-mode and the secondary oscillation mode is a B-mode.

5. The crystal oscillator device according to claim 4, further comprising

a beat signal extraction unit, loosely coupling the B-mode oscillation signal to the C-mode oscillation signal and extracting a beat signal from the B-mode signal and the C-mode signal as temperature information to the crystal unit.

6. The crystal oscillator device according to claim 4, further comprising

a temperature compensation control unit calculating a value representing an oscillation frequency of the beat signal from the C-mode oscillation signal and the B-mode oscillation signal with reference to the oscillation frequency of the C-mode oscillation signal, executing temperature compensation control based on the value representing the oscillation frequency of the beat signal when fluctuation of the value representing the oscillation frequency of the beat signal is small, and executing temperature compensation control based on the value representing the oscillation frequency of the beat signal and a primary specified value when fluctuation of the value representing the oscillation frequency of the beat signal is large.

7. The crystal oscillator device according to claim 6, wherein the temperature compensation unit executes temperature compensation control based on a secondary specified value when the value representing the oscillation frequency of the beat signal indicates lower than a temperature 1, and executes temperature compensation control based on a tertiary specified value when the value representing the oscillation frequency of the beat signal indicates equal or higher than a temperature 2, which is higher than the temperature 1.

8. The crystal oscillator device according to claim 6, further comprising

a primary temperature detector unit detecting whether a temperature in a proximity of the crystal unit is lower than a temperature 1 or not;

and

a secondary temperature detector unit detecting whether the temperature in the proximity of the crystal unit is equal or higher than a temperature 2 or not, which is higher than the temperature 1, wherein

the temperature compensation control unit executes temperature compensation control based on a secondary specified value when the primary temperature detector unit detects that the temperature in the proximity of the crystal unit is lower than the temperature 1, and executes the temperature compensation control based on a tertiary specified value when the secondary temperature detector unit detects that the temperature in the proximity of the crystal unit is equal or higher than the temperature 2.

9. The crystal oscillator device according to claim 1 further comprising a heater unit, which is configured to coincide with a terminal of the crystal unit, heats the crystal unit through the terminal.

10. The crystal oscillator device according to claim 9 further comprising a power transistor, which drives the heater unit, wherein the power transistor is in thermal contact with the crystal unit.

11. The crystal oscillator device according to claim 1, further comprising a package, which vacuum-seals elements configuring the crystal oscillator device.

12. A crystal oscillator device, for simultaneously generating oscillation signals with a plurality of oscillation modes of a crystal unit, comprising:

primary resonator means for filtering the oscillation signal with a primary oscillation mode, which is one of the oscillation modes, from the output of the crystal unit;

secondary resonator means for filtering the oscillation signal, bearing a different resonant frequency from that of the primary resonator means with the primary oscillation mode from the output of the crystal unit;

primary phase synthesis means for synthesizing the phases of the output signal of the primary resonator means and the output signal of the secondary resonator means;

tertiary resonator means for filtering the oscillation signal with a secondary oscillation mode, which is one of the oscillation modes, from the output of the crystal unit;

quaternary resonator means for filtering the oscillation signal, bearing a different resonant frequency from the tertiary resonator means, with the secondary oscillation mode from the output of the crystal unit; and

a secondary phase synthesis means for synthesizing the phases of the output signal of the tertiary resonator means and the output signal of the quaternary resonator means,

wherein the primary phase synthesis unit and the secondary phase synthesis unit are a differential amplifier.

13. A oscillation method in a crystal oscillator device, wherein oscillator signals are generated simultaneously with a plurality of oscillation modes of a crystal unit, comprising:

passing the output of the crystal unit through resonators with both sides of resonance frequency of a primary oscillation mode frequency, which is one of the oscillation modes, and generating the feedback signal and the oscillator signal of the primary oscillation mode by phase-synthesis of each output signals; and

passing the output of the crystal unit through resonators with both sides of resonance frequency of a secondary oscillation mode frequency, which is one of the oscillation modes, and generating the feedback signal and the oscillator signal of the secondary oscillation mode by phase-synthesis of each output signal of the second resonators,

wherein the primary phase synthesis unit and the secondary phase synthesis unit are a differential amplifier.