Impedance matching method and apparatus for electret microphone, and communication device

An impedance matching apparatus for an electret microphone, comprising a processor configured to:

• measure a bias voltage output by the electret microphone;
• determine whether the bias voltage is within a preset bias voltage threshold range;
• and
• adjust load bias impedance such that the bias voltage is within the preset bias voltage threshold range, in response to determining that the bias voltage is not within the preset bias voltage threshold range,
• wherein the load bias impedance includes a resistance of a bias resistor connected between a drain of a field effect transistor disposed in the electret microphone and a supply voltage of the electret microphone.

A non-transitory computer storage medium storing a plurality of computer-executable instructions that, when executed by an apparatus for impedance matching for an electret microphone, causes the apparatus to perform the method of:

• measuring a bias voltage between a source and a drain of a field effect transistor disposed in the electret microphone;
• determining whether the bias voltage is within a preset bias voltage threshold range;
• and
• adjusting load bias impedance such that the bias voltage is within the preset bias voltage threshold range, in response to determining that the bias voltage is not within the preset bias voltage threshold range,
• wherein the load bias impedance includes a resistance of a bias resistor connected between the drain of the field effect transistor and a supply voltage of the electret microphone.