Conductive,dielectric and amalgamated obstacles coupled waveguide based highly selective multiband bandpass resonators

Abstract

This paper demonstrates transverse nonplanar resonators consisting of symmetrically placed obstacles (posts which made up of same or different type of materials) coupled into rectangular waveguide. Introducing posts inside a waveguide in proposed structure creates discontinuity and become a cavity resonator. Resonance is created at X band, Ku band and Ka band frequencies are reported. Simulation results demonstrates that resonators's results are matched to free-space as well as having a superior insertion loss and better return loss of conductive posts compare to dielectric posts. Moreover, obstructing the E-field (using conductive posts) compare to the H-field (using dielectric posts) are given better insertion loss and impedance matching characteristics. However, insertion of amalgamated obstacles into rectangular waveguide generates good transmission and reflection zeros compared to other two topologies at resonant frequencies which are described here. Posts coupled waveguide resonators having high power handling capacity so it can be utilized for Base transceiver station, Satellite Communication, Space applications, sensors as well as the fusion plasma diagnostics system. All the proposed structures are simulated with Ansoft's finite-element High Frequency Structure Simulator (HFSS) tool to demonstrate the characteristics of the resonators using a rectangular waveguide with center frequency of 11.2 GHz for X-band. In addition, the equivalent model of resonator is simulated in ADS (Advance designing system). It is observed that offered topologies are very sensitive to the parameters deviation (Post coupled waveguide resonator performance depends on diameter of conductive post, elevation of post and detachment between posts).