X-Band Waveguide Mechanical Damper Enabled by 3D Printed Flexible Corrugations and Dielectric Loaded Chokes

In modern Radio Frequency (RF) systems, long waveguide chains are routed as transmission lines to connect the RF source to the antenna. These systems are subjected to mechanical shock and vibration, along with undesired thermal expansion during transportation or operation. Since waveguides are rigid mechanical pipes, they may face catastrophic failure due to mechanical stresses. Thus, this paper investigates a novel waveguide-based damper in the X-band with 93.33% transmission efficiency from 9.5 GHz to 11.5 GHz, which is enabled by 3D printing of flexible dielectrics to act as a mechanical isolator. The 3D-printed flexible dielectric used is Thermoplastic Polyurethane (TPU) which allows for flexible corrugations to be designed between two waveguide interfaces that are separated by some distance. To reduce the RF leakage due to the gap between the waveguide, dielectric-loaded RF chokes are introduced. The dielectric-loaded RF chokes also provide mechanical functionality of the waveguide mechanical damper by implementing corrugations as part of the choke design, allowing for shocks and acceleration to 20G. This allows the two gap waveguides to support the transient mechanical displacements of the waveguide flange during transportation, acting as a mechanical damper between two waveguide subassemblies.