Abstract-5G new spectrum radio access should support data rates exceeding 10 Gbps in most of its applications. An Ultra Wide Band (UWB) Ultra-high data rate Wilkinson power divider up to 6.9 Gbps for 5G new spectrum and CAR applications is presented in this paper. The step by step design procedure, optimization and implementation of this Wilkinson power divider in 20-30 GHz are completely done to achieve the optimum performance. The final fabrication results show the average of −14 dB of input matching, −20 dB of isolation of isolated Ports, −4.2 dB of coupling in output ports (considering 2 SMA connectors and transitions in each path), and linear phase variation of outputs in the whole bandwidth of 20-30 GHz. During the design procedure, a new and very useful coaxial to microstrip transition in K-band is designed, analyzed, developed and fabricated to achieve the best results. Also a complete study of time domain analysis with ultra-high data rate signal is presented to minimize the total reflection coefficient caused by the partial reflections from several discontinuities. To complete and validate the final fabricated Wilkinson power divider in ultra-high data rate application in 5G new spectrum, the extracted results of UWB-IR impulse radio with modulated ultra-high data rate signal up to 7 Gbps and in 20-30 GHz bandwidth is completely done. The measured results show that this fabricated Wilkinson power divider can handle a periodic modulated signal up to 7 Gbps, which are valuable results for many applications in 5G and CAR systems.