We are trying to identify the root cause of an issue with the tuning of an RF circuit on FR-4 laminate. We are seeing a major shift in the attenuation of the received signal from room temperature (~20 deg. C) to high operating temperature (~60 deg. C).  I know that the volume and surface resistivity of FR-4 (GF/GFN) can change by a factor of up to 10^2 over the working temperature range of the laminate. Does this shift in performance also track with the dielectric constant and loss tangent of the material? If so does anyone have documentation as to how these properties change over working temperature?

Thanks for any input.

Jeffrey A McGlaughlin, CID
Engineering Designer
Battelle
Systems Development Engineering Services
505 King Ave
Columbus Ohio 43201-2693
Phone (614)424-7582
 [cid:[log in to unmask]]




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