1990 Volume 11 Issue 6 Pages 327-333
The improvement in performance of the microphone using piezoelectric creamic which includes the FET circuit, is described in this research report. The most important point in the design of the microphone is how to improve the transduction efficiency. This paper analyzes a microphone as a system consisted of a number of subsystems. Suppression of the energy transmission loss between these subsystems is an important requirement in designing the microphone. This paper also solves this problem by dividing the electrode of the piezoelectric ceramic and connecting the divided electrodes in series. A large output is obtained by input of high voltage into the FET which has voltage drive characteristics. High performance and stability were obtained by this microphone together with the use of ceramic for the entire diaphragm system in the prototype microphone. The performance characteristics of this prototype microphone are Sensitivity:-35.8 dB/Pa 1 kHz, Electrostatic capacitance: 275 pF, Frequency response:±1.5 dB at 20 Hz to 12.5 kHz.
