GaN-HEMTs allow power converters to achieve high switching frequencies. Therefore, novel design challenges arise in both power and frequency. In this context, this work aims to contribute with the integration of design concepts inspired both from power electronics and radio-frequency methods by using transmission-line approach. The developed study presented here focuses on the gate signal. Nevertheless, this methodology can be extended to any other power converter signals. The explored methodology associates coplanar transmission lines with the IPC9592B PCB design standard for the design of the gate PCB-trace layout. Experimentally, a Vector Network Analyzer verifies the transmission line parameters of the designed gate layout. Additionally, the gate signals are compared for different power levels in a high-frequency boost converter. Study results provide insights about the transmission line methodology for the development of high-frequency power converters based on GaN-HEMT.