https://www.minicircuits.com/products/LTCC-Ceramic-RF-Filters.html

Low Temperature Co-Fired Ceramic (LTCC) filters are fabricated by combining thin layers of ceramic substrate with conductive metalizations and sintering the layers together to create three-dimensional filter circuits enclosed in tiny ceramic monoliths. LTCC filters are extremely rugged and suitable for harsh operating environments while their low cost and repeatable performance make them ideal for high-volume production. They are also extremely tiny, allowing designers to minimize system size and weight compared to other technologies. Mini-Circuits is an industry leader in LTCC filter design with over 300 models in stock and 22 years of design experience. Our filter designs combine state-of-the-art materials and filter topologies with advanced characterization and modelling, simulation tools and design workflows to achieve outstanding rejection and selectivity up to millimeter wave bands.