ENGINEERING ANSWER
Two-layer boards can provide simple RF paths and accessible launches. Four-layer boards can add routing and power-distribution options, but require a defined bonding system and careful return-path planning.
What to decide before release
Choose layer count from the signal and power architecture, mechanical requirements and assembly density. Keep the RF reference plane close and continuous. Compare the complete stackup and manufacturing cost before choosing.
Checks to put in your design brief
- Identify all routing needs
- Review reference-plane continuity
- Check mechanical thickness requirements
Important distinction
More layers do not automatically deliver lower loss or better isolation. Layout and transitions remain decisive.
Sources & basis
Material facts follow the cited source. Design checks are preliminary guidance, not supplier process instructions.