I am Currently designing a 4 layer RF PCB for which I require impedance control trace for antenna connections. the two inner layers are gnd and power layers. I have knowledge that trace impedance depends of PCB material used and its thickness. Kindly guide if the inner layer used for power and gnd should be conductor /plane. Because as i change the layer type the width of the trace becomes less for 50 ohm impedance approx 10 mils. while changing them to conductor increases the trace width.
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