Microstrip vs. Stripline: Choosing the Right High-Speed Geometry.

Traces created using microstrip will be routed on the outer layers of a PCB with only one reference plane and will be run within two reference planes when using stripline. Microstrip traces are easier to access and check than stripline traces, but they are also at greater risk of electromagnetic interference (EMI) and size variations than stripline traces. Stripline provides better shielding from EMI than microstrip does, has more consistent impedance than microstrip does, and usually emits less radiation than microstrip does. For these reasons, the use of stripline tracers is recommended for any high-speed applications where a weak indication of noise will interfere with your work. On the other hand; if you are designing a PCB with a lower degree of complexity and will be using it for an economy-based project, then microstrip is your best choice. Your decision as to the type of geometry you ultimately choose (microstrip vs stripline) will be determined by the total number of layers in your stackup, the speed of your signals and; most importantly, the amount of EMI generated by your PCB design efforts.