Length of Transmission Line & Characteristic Impedance
The height of a line (thickness of dielectric) affects both its capacitance and inductance. The width of a line affects both its capacitance and inductance. The length of a line affects only its delay, and its attenuation.

If a transmitter and an antenna are the same impedance, and connected by a line of that impedance, then the length of the line connecting them is irrelevant (except for ohmic losses causing attenuation).

However, often the transmitter isn't matched for some reason, power or efficiency, and the antenna may not be matched, perhaps for space, and the line between them is used for matching. In that case, the maximum matching effect can be achieved with a \$\lambda/4\$ or odd multiples of that length line. With a \$\lambda/2\$ line or multiples, no matching impedance transformation is achieved, regardless of the line impedance.