ENGINEERING ANSWER
Millimeter-wave suitability depends on the entire construction and required performance. RO4350B should not be advertised with a universal maximum usable frequency or automatic 77 GHz qualification.
What to decide before release
Compare candidates using measured loss, roughness, dimensional capability and available design models at the intended band. Evaluate launch and antenna performance as well as straight-line attenuation. Consider purpose-selected lower-loss materials when the budget demands them.
Checks to put in your design brief
- Set a quantitative loss budget
- Request frequency-relevant material data
- Prototype the critical structures
Important distinction
Passing a laminate specification is not a system-level qualification for automotive radar or another millimeter-wave product.
Sources & basis
Material facts follow the cited source. Design checks are preliminary guidance, not supplier process instructions.