ENGINEERING ANSWER
A good material decision connects a performance requirement to a manufacturable, available construction. The material name, datasheet values, model and acceptance test should tell a consistent story.
What to decide before release
Write down the operating band, maximum path loss, phase/impedance needs, thermal environment and mechanical limits. Compare a small set of exact material/foil combinations, then confirm fabrication capability and prototype evidence.
Checks to put in your design brief
- Use comparable data conditions
- Model the actual geometry
- Obtain a written stackup and quotation
Important distinction
Do not rank materials using a single dielectric constant, a generic price claim or an unverified “best for” label.
Sources & basis
Material facts follow the cited source. Design checks are preliminary guidance, not supplier process instructions.