MICROWAVE CAV

ITY FIL

TER

SHOCK AND VIBRATION MODAL A

NALYSIS

Don Blanchet3B Associates4/12/1999

sighting electronics

POSSIBLE SITUATIONS OF CONCERN – NOISE SOURCES

GOALSIdentify the modal vibration resonant frequencies of a

microwave cavity filter and its tuning elements.

Provide the results to the electronic engineering staff.

Understand self generated electrical signal noise due to mechanical shock sources such as:pyrotechnic explosive events – shipboard rapid gun fire HALT testing with hammer blows

WARNING HALT/HASSMicrowave engineers – please note HALT “vibration” machines

use hammer blows to generate 3 axis excitation.The exciting signal felt by the tested units will have significant

shock components above 2KHz.Very small components can be damaged during HALT and

HASS.

MODEL MICROWAVE CAVITY FILTER

Gold plated 6061-t6 aluminum

MODEL – COVER REMOVED

Interdigital microwave filter elements

FINITE ELEMENT MESH

71,000 degrees of freedom

RESULTS FEA EIGENVALUE EXTRACTION

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RESULTS SUMMARY