Investigation of Cavity Fabrication Methods for Integrated Horn Antenna Structures in Low Temperature Cofired Ceramic (LTCC) Substrates

This article investigates various fabrication methods for integrated horn antenna structures in a ceramic multilayer substrate and presents a fundamental investigation for a following silicon-ceramic-based space sensing sensor. Precise alignment of the individual tape layers, via placement and implementation of the cavity design is crucial for this application. Due to processrelated circumstances, cavity deformations and other undesirable defects affect the ceramic horn antenna structure. Different realization methods for cavities are investigated, e.g., fabrication in the green state of the ceramic and after the sintering process. The cavities are evaluated using x-ray examination, cross section, and scanning electron microscopy. By inserting carbon inlays into the cavities before the sintering process, the quality of the desired geometry is significantly increased. Furthermore, parameters for cavity fabrication after sintering using cold laser ablation were investigated and the feasibility of inclined sidewalls was demonstrated.