Impedance Matching on RF board(CC2541- BLE)

Hello,

We are developing RF PCB based on CC2541. We refers to tidrc156a.zip, it is dual layer postage stamp reference design guide included gerber data and drill data.

Here transmission line width is 0.3mm(Dielectric - FR4  0.8mm copper thickness 35um each layer).

For our PCB we are confused which calculator to be used to calculate transmission line width   either microstrip or CPW(Co-planar wave).

 Microstrip Impedance calculator reflects width of 1.41mm and

CPW calculator reflects width of 1mm.

Still these is much differencein transmission line width  between the reference(tidc156a.zip) and calculator value whether it may be microstrip or CPW.

Our board specifications are:-

Dielectric width 0.8mm, copper thickness 35um, Dielectric coefficient 4.6 and operating frequency 2400MHz.

Please guide us which calculator to be used and how to calculate the transmission line width to match impedance correctly.

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