Thermoplastic Green Machining for Textured Dielectric Substrate for Broadband Miniature Antenna

A textured dielectric substrate for a broadband miniature antenna was fabricated using a thermoplastic green machining. This substrate comprised of three steps with optimized distribution of a dielectric ceramic (Bi–Ba–Nd–Titania; BBNT) and an epoxy. At first, a thermoplastic compound, consisting of BBNT particles and thermoplastic binders, was machined precisely using a mini-computer numeric controlled machine to make a three-dimensional void in the green BBNT body. After appropriate binder removal and sintering, the void in the dense BBNT block was filled with an epoxy to fabricate a textured dielectric substrate. The BBNT sample was characterized by several analyzing tools in terms of machinability, microstructural evolutions, chemical compositions, crystalline phase, and dielectric properties. Bandwidth and gain of the patch antenna with the textured dielectric substrate were measured and compared with the simulated results.