A lego-like reconfigurable cavity using 3-D Polyjet technology

Combination of lego-like tuning post cavity structure and 3-D Polyjet printing is utilized to demonstrate a high Q X-band resonator for the first time. The dominant mode is TEioi mode with the resonant frequency of 8.31 GHz. The Polyjet printing techniques is one of the state-of-art additive manufacturing technologies, as it allows for high resolution modeling, fast and low cost prototyping. Here the cavity is assembled by two 3-D Polyjet printed half pieces through a lego-like process. Six tuning posts are used to perturb the field inside the cavity, making such cavity to be reconfigurable by tuning the resonant frequency. Simulations were carried out using a commercial FEM simulation tool and measurements are carried out over a frequency range of 8-10 GHz. Simulation and measured results match very closely. About 0.1% frequency shift and an unloaded quality factor of 391 were measured for the resonator with no perturbation. An average of 1.05% of frequency shift as well as the average quality factor of 169 at all the tuned resonant frequencies were also observed. This paper demonstrates that a combination of 3-D Polyjet printing techniques and novel reconfigurable cavity structure can be used for the fabrication of RF structures that are traditionally hard and expensive to manufacture.