Accession Number:

ADA346276

Title:

Shielding Effectiveness of a Thin Film Window

Descriptive Note:

Final rept. Sep 97-Feb 98

Corporate Author:

AIR FORCE RESEARCH LAB KIRTLAND AFB NMDIRECTED ENERGY DIRECTORATE

Personal Author(s):

Report Date:

1998-04-01

Pagination or Media Count:

69.0

Abstract:

The thin film investigated was designed to protect infra-red IR systems from electromagnetic interference EMI, yet allow IR to pass through the thin film window. This experiment measured the properties of a thin film developed by Sienna Technologies, Inc., through a Phase II Small Business Innovative Research SBIR program. The objectives of this SBIR were to shield the system from EMI by at least 20 dB from 400 MHz to 18 GHz, and transmit at least 90 of the IR around 1 micrometer and between 8 - 12 micrometers. The measured shielding effectiveness of the thin film was 25 dB from 4 GHz to 12 GHz. The predicted shielding effectiveness was 29 dB based on theoretical calculations. The error analysis of the shielding effectiveness showed that this predicted value was within the measurement error of the experiment. The shielding effectiveness of the substrate was also measured, and it did not contribute to the shielding effectiveness of the thin film. Shielding effectiveness was measured in an electronically mode-stirred reverberation chamber to get a quick overview and in an anechoic chamber to measure the shielding effectiveness versus incident angle. The IR transmission of the thin film could not be determined because of the low IR transmission through the substrate.

Subject Categories:

  • Inorganic Chemistry
  • Electricity and Magnetism
  • Solid State Physics
  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE