Optimization of dry powder deposition parameters for production of large substrates using functionally graded ceramics

Official URL: http://dx.doi.org/10.1111/ijac.12887

The ability to control the spatial variation in three dimensions of dielectric properties is known to play a crucial role in achieving novel electromagnetic performance such as miniaturization and high gain of broadband antennas. To address this need, the objective in this paper is to use earlier proposed Dry Powder Deposition to produce large substrates of Functionally Graded Materials with spatially controlled CaTiO3 − MgTiO3 − Mg2TiO4 dielectrics. We present an in-depth analysis and optimization of critical processing parameters such as compaction pressure, sintering temperature and dwell time. Using the optimized compaction and co-sintering process, spatially varying large (12cm x 12cm) substrates were produced without the presence of cracks, warping and undesired porosities. In addition to these structural functionalities, sintered ceramic constituents of the designed substrate display targeted dielectric permittivity values of a miniaturized broadband Satellite Communication Ultra High Frequency antenna at the optimized conditions. This optimized route opens up possibilities for multi-functional metrics to be addressed for other applications calling for different spatial distributions of large Functionally Graded Materials possibly with the same family of ceramic constituents.