Patent No. | 9,263,989 |
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Issue Date | February 16, 2016 |

Title | Differential Oscillator |

Inventorship | Takashi Nakaoka, Saitama (JP) Hiroshi Hoshigami, Saitama (JP) |

Assignee | NIHON DEMPA KOGYO CO., LTD., Tokyo (JP) |

1. A differential oscillator, comprising:

a resonator that has at least a first resonance mode and a second resonance mode;

a differential amplifier circuit configured to oscillate the resonator;

a filter disposed in parallel to the resonator and the differential amplifier circuit, the filter having a first resonance

frequency in the first resonance mode and a second resonance frequency in the second resonance mode, a first impedance of

the filter at one of the first resonance frequency and the second resonance frequency is lower than a second impedance of

the filter at another one of the first resonance frequency and the second resonance frequency, wherein

the differential oscillator has a negative resistance at a frequency at which the second impedance of the filter is higher

while the differential oscillator does not have a negative resistance at a frequency at which the first impedance of the filter

is lower, among the first resonance frequency and the second resonance frequency.

a resonator that has at least a first resonance mode and a second resonance mode;

a differential amplifier circuit configured to oscillate the resonator;

a filter disposed in parallel to the resonator and the differential amplifier circuit, the filter having a first resonance

frequency in the first resonance mode and a second resonance frequency in the second resonance mode, a first impedance of

the filter at one of the first resonance frequency and the second resonance frequency is lower than a second impedance of

the filter at another one of the first resonance frequency and the second resonance frequency, wherein

the differential oscillator has a negative resistance at a frequency at which the second impedance of the filter is higher

while the differential oscillator does not have a negative resistance at a frequency at which the first impedance of the filter

is lower, among the first resonance frequency and the second resonance frequency.