| 摘要 |
PROBLEM TO BE SOLVED: To provide a condenser microphone in a high sensitivity. SOLUTION: In a condenser IC microphone manufactured by using a microphone processing technology making full use of semiconductor manufacturing technology, an oscillation frequency of LC oscillation circuit at an oscillation- modulation circuit 5 is changed according to the change of capacity of a condenser consisting of an oscillation electrode 1 and a back electrode 2 responding to the change of sound pressure. An oscillation output signal from the LC oscillation circuit is FM modulated responding to the change of sound pressure so as to transmit from an antenna 6. A change of capacity of the condenser, which change is caused by the sound pressure, is read as a change of frequency oscillated from the LC oscillation circuit having the condenser as a part of capacitance, so that a separation between the electrodes 1 and 2 is lessened and the sensitivity of the microphone is become in a high sensitivity without any necessity of applying a strong bias voltage to the IC microphone.
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