Simulation, Fabrication & Analysis of a Solid Dielectric Waveguide for X-Band Microwave Systems

Sammanfattning

This study features the design, simulation, fabrication, and experimental characterisation of solid dielectric rectangular waveguides integrated with WR102 metallic waveguides. The waveguides are designed to operate over a frequency range of 7.5 to 8.5 GHz. Two dielectric materials are investigated: Polylactic Acid (PLA) and Polypropylene (PP). Various tapering methods are tested to improve impedance matching and minimize signal loss. The models are then simulated in Keysight EMPro using the Finite Element Method (FEM). Following simulation, physical prototypes are fabricated with Fused Deposition Modelling(FDM), 3D printing for each material. Scattering parameter measurements are performed using a Vector Network Analyser (VNA) connected to WR102 coaxial-to-waveguide adapters at each port. Simulation and measurement results are compared in terms of S21 insertion loss and S11 return loss at the frequency band. The study demonstrates the strong dependence of waveguide performance on geometry, material properties, and physical dimensions in 7.5 - 8.5GHz frequency band. However, discrepancies between simulated and measured results are observed, primarily due to fabrication tolerances and uncertainties in material parameters.