The width of the strip, the thickness of the substrate and the relative permittivity of the substrate determine the characteristic impedance of the strip which is a transmission line. As shown in the diagram, the central conductor need not be equally spaced between the ground planes.
The width of the strip, thickness of the substrate, and relative permittivity of the substrate determine the characteristic impedance of the transmission line. As depicted in the diagram, the central conductor need not be evenly spaced between the ground planes.