ENGINEERING ANSWER
Base-station feed networks depend on amplitude and phase balance, conductor loss and stable geometry across a panel. The substrate decision interacts with line length, power handling and the antenna assembly.
What to decide before release
Allocate loss and phase budgets to each branch. Keep routing environments consistent and include connectors, dividers and mechanical structures in the model. Measure representative assemblies over the intended band and environment.
Checks to put in your design brief
- Define channel balance targets
- Model long feed runs
- Check mechanical and thermal conditions
Important distinction
A nominal dielectric constant cannot by itself guarantee beam shape or array efficiency.
Sources & basis
Material facts follow the cited source. Design checks are preliminary guidance, not supplier process instructions.