The 3 dB, 90° coupler is a passive device with four ports that allows each output to collect half the input power but in phase quadrature. The 3 dB coupler is often made in microstrip technology where different quarter-wave sections are present to ensure impedance matching. In order to be able to design a duplexer operating on several frequency bands, a tunable hybrid coupler was designed in this work. The coupler must be adjustable to operate on the bands 3.3-3.6 GHz and 4.8-5 GHz. The proposed coupler will cover the bandwidth requirements of 5 bands (3.3-3.6 GHz) and (4.8-5 GHz) to be deployed in China. The hybrid coupler will be designed by two methods. At the first stage, the coupler will be designed by lumped elements, and then it will be designed using transmission lines. Via the ADS tool, the 3 dB 90° coupler is dimensioned and simulated to work well at the center frequency of 3.45 and 4.9 GHz. These two frequencies are belonging to the 5G bands. The main purpose of this work is to simulate and analyze the proposed coupler for 5G frequency bands. The simulation of the reflection coefficient, i.e., S11 parameters in amplitude and phase are presented and discussed. From simulation results we observed that the proposed coupler works under the requirement of 5G application.