Patent ID: 7463085

Claim:
A tuning circuit comprising: a current generation unit comprising: a first transistor having a first terminal, a second terminal, and a third terminal, said first transistor for changing a current flowing from the second terminal to the third terminal in proportion to a first voltage applied to the first terminal, and a variable resistor unit with a variable resistance, said variable resistor unit electrically connected to the third terminal of the first transistor, a current flowing at the variable resistor unit changeable according to a resistance selected for the variable resistor unit; and a capacitance correction unit comprising: a second transistor having a fourth terminal, a fifth terminal, and a sixth terminal, said second transistor forming a current-mirror circuit together with the first transistor in which a mirror-current flows from the fifth terminal to the sixth terminal in proportion to a second voltage applied to the fourth terminal, and a variable capacitor unit with a variable capacitance, said variable capacitor unit connected with the sixth terminal.