US Patent No. 9,240,755

OSCILLATOR CIRCUIT


Patent No. 9,240,755
Issue Date January 19, 2016 
Title Oscillator Circuit
Inventorship Masaki Hirose, Kanagawa (JP)
Yukio Akazawa, Kanagawa (JP)
Hiroki Hamaguchi, Kanagawa (JP)
Takehito Ishii, Saitama (JP)
Noritoshi Kimura, Saitama (JP)
Assignee NIHON DEMPA KOGYO CO., LTD., Tokyo (JP)

Claim of US Patent No. 9,240,755

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.