Development of PVF2 Noise-Cancelling Microphone

Abstract

This report describes the theory, development, and performance of a noise-cancelling microphone for military use. The generating element is a bimorph annulus, constructed by bonding plastic films of piezoelectric PVF2 (polyvinlidene fluoride) to a central shim of aluminum. The aluminum shim controls the stiffness of the bimorph so that wide-bandwidth operation is obtained over a temperature range of -51 C to +71 C. The fundamental resonance frequency is above the speech frequency range so that damping structures are not required. The microphone includes a preamplifier. The microphone assembly is similar to that of a previously developed piezoceramic microphone. The sensitivity of the PVF2 bimorph is 10 dB less than that of the piezoceramic bimorph. The PVF2 film has a deposited aluminum electrode which was found to require careful handling to avoid loss of electrical continuity. Except for considerations of the integrity of the PVF2 electrode, the PVF2 material provides a rugged, highly-linear, noise-cancelling microphone. Author

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1979
Accession Number
ADA067276

Entities

People

  • A. J. Brouns

Organizations

  • Vought

Tags

Communities of Interest

  • Advanced Electronics
  • Energy and Power Technologies
  • Space
  • Weapons Technologies

DTIC Thesaurus Topics

  • Air Force
  • Capacitance
  • Circuits
  • Crystal Structure
  • Electrical Impedance
  • Electromagnetic Fields
  • Electronics
  • Electronics Laboratories
  • Field Effect Transistors
  • Low Temperature
  • Material Degradation Processes
  • Measurement
  • Military Research
  • Modulus Of Elasticity
  • Piezoelectric Materials
  • Sound Pressure
  • Transducers

Readers

  • Microwave Engineering.
  • Polymer Science and Engineering.
  • Speech Processing/Speech Recognition.