Open AccessDelta‐sigma modulation microphone sensors using microwave cavity resonator
Author(s) -
Maezawa K.,
Fujino S.,
Yamaoka T.,
Mori M.
Publication year - 2016
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2016.2538
Subject(s) - delta sigma modulation , microphone , modulation (music) , resonator , acoustics , microwave , electronic engineering , electrical engineering , noise (video) , frequency modulation , signal (programming language) , digital signal , engineering , physics , computer science , telecommunications , digital signal processing , radio frequency , sound pressure , cmos , image (mathematics) , programming language , artificial intelligence
The frequency delta‐sigma modulation (FDSM) technique was applied to the microphone sensors. The FDSM is a superior analogue‐to‐digital conversion technique, which outputs wide band, large dynamic range digital signals without precision analogue components. In this implementation, a microwave cavity resonator having movable membrane on its one end, together with a gain block consisting of a heterojunction field effect transistor, was used for sound‐frequency converter. The output of this converter (frequency modulated intermediate signal) was sampled and converted to 1‐bit delta sigma modulated digital signals. The noise shaping behaviour with a clear signal peak was demonstrated for the fabricated devices.