Tasarım optimizasyonu ile geliştirilmiş MEMS mikrofon frekans yanıtı

Abstract

Mikrofonun temel özelliği, gelen akustik sinyali sadık bir şekilde algılamak ve elektrik sinyaline dönüştürmektir. Yarı iletken tabanlı kapasitif MEMS mikrofonlar, sınırlı boyutlarına rağmen dikkate değer performanslar (frekans tepkisi, SNR) sunmaktadır. Bu makalenin amacı, mevcut SDM (Sealed-Dual-Membrane) kapasitif MEMS mikrofonunda özellikle havalandırma deliğinin konumu ile ilgili bazı tasarım optimizasyonlarını tanıtmaktır. Önerilen değişikliklerin mikrofonun performansı üzerindeki etkileri Lumped Model simülasyon aracı kullanılarak değerlendirilmiştir. Mikrofonun genel performansında (SNR) daha az önemli bir iyileşme elde edilse bile, ses bandı içinde cihaz frekans yanıtında net bir iyileşme elde edilmiştir.

Keywords

• kapasitif MEMS mikrofon
• frekans cevabı
• topaklı model
• havalandırma deliği
• arka hacim.

Improved MEMS microphone frequency response through design-optimization

Abstract

Microphone main characteristic is to faithfully detect and transform incoming acoustic signal in electric one. Semiconductor based capacitive MEMS microphones, despite their limited dimensions, offer remarkable performances (frequency response, SNR). The purpose of this article is to introduce some design optimizations in the current SDM (Sealed-Dual-Membrane) capacitive MEMS microphone mainly concerning the position of the ventilation hole. The effects of the suggested modifications on the microphone’s performances were evaluated using Lumped Model simulation tool. A clear improvement in the device frequency response within audio-band was obtained even if a less significant improvement in the general performances of microphone (SNR) was achieved.

Keywords

• capacitive MEMS microphone
• frequency response
• lumped model
• ventilation hole
• back-volume.

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