Compact microstrip diplexer design using new octagonal resonators for 5G and Wi-Fi applications

Abstract

The present paper sheds light on designing a new and high performance microstrip diplexer. The latter is based on new octagonal meandrous resonators combined with the connected common port, without adding any transmission line junction, in order to get a miniaturized structure. The suggested compact resonator is formed through combining the octagonal meandrous lines and coupled lines, which create a bandpass filter. These filters operate at 3.5 GHz and 5 GHz which make them suitable for 5G and Wi-Fi applications. Accordingly, an approximated equivalent LC model of the presented octagonal meandrous resonator is suggested and analyzed so as to validate the simulation results. On top of that, the suggested diplexer is compact, as it occupies only 0.0768 λ g × 0.024 λ g. Thus, it attained excellent performance in terms of S-Parameters as the transmission coefficients are about -1 dB and the reflection coefficient is about -20 dB at both channels, whereas the isolation is about -25 dB. Hence, the validation of theoretical and simulated results is carried out through measurements of the manufactured prototype.