An E-band Diplexer for Gigabit Wireless Communications Systems

Abstract

In this thesis, microwave diplexers are designed by different methods using rectangular waveguide cavities with chebyshev response. The diplexers can be used as front-end components in E-band [CH1:71-76 GHz and CH2:81-86 GHz] transceivers that are used in point-to-point mobile backhaul applications to offer gigabit wireless connectivity over a distance of a mile or more. Two diplexers have been designed, a T-junction diplexer and a manifold diplexer. The T-junction diplexer has been designed by using two waveguide-cavity band-pass filters and then, the two filters are connected by a common H- plane T-Junction to divide power between filters equally. The manifold diplexer has been designed by connecting the channel filters by the manifold (transmission line sections and T-junctions). Each channel filter has been designed of five waveguide cavities coupled together using inductive apertures. An EM simulation software CST has been utilized to design the diplexers by employing both parameter sweep and optimization techniques to achieve the required response. The simulation results show that the responses of both diplexers meet the requirements of the E-band diplexers in terms of return loss and isolation.