Segura-Gómez, CleofásBiedma-Pérez, AndrésSantiago Arriazu, DavidPalomares-Caballero, ÁngelArregui Padilla, IvánGómez Laso, Miguel ÁngelPadilla, Pablo2025-07-032025-07-032025-03-01Segura-Gómez, C., Biedma-Pérez, A., Santiago, D., Palomares-Caballero, Á., Arregui, I., Laso, M. A. G., Padilla, P. (2025) Cavity-stacked filter in CLAF-SIW technology for millimeter waves. AEU - International Journal of Electronics and Communications, 193, 1-7. https://doi.org/10.1016/j.aeue.2025.1557251434-841110.1016/j.aeue.2025.155725https://academica-e.unavarra.es/handle/2454/54379This work presents the design of a cavity-stacked bandpass filter (BPF) using contactless air-filled substrate integrated waveguide (CLAF-SIW) technology for millimeter-wave frequencies. This technology is a variant of air-filled SIW technology, incorporating contactless techniques. It enables the reduction of dielectric losses in SIW filters while supporting multilayer structures with robust assembly. The cavity-stacked filter topology allows for very good frequency responses with a reduced footprint and no transitions needed. As an example, a 4th-order Chebyshev bandpass filter composed of four stacked cavities, coupled through irises, is shown. The iris layers are fabricated by metallizing the slot edges of a PCB, while the cavity layers are implemented using CLAF-SIW. The filter has been designed and manufactured to provide a passband response from 36 GHz to 37.5 GHz. A good agreement between measurement and simulation has been achieved. The losses in the proposed CLAF-SIW filter are primarily due to the metal roughness of the low-cost commercial laminates used.application/pdfeng© 2025 The Authors. Published by Elsevier GmbH. This is an open access article under the CC BY-NC license.Cavity-stacked filtersChebyshev filterCLAF-SIW technologyElectromagnetic bandgapMillimeter wavesPlanar technologiesinfo:eu-repo/semantics/article2025-07-03info:eu-repo/semantics/openAccess