In this paper. a narrowband bandpass filter comprising substrate integrated waveguide (SIW) and spoof surface plasmon polaritons (SSPPs) is proposed. achieving miniaturization and low insertion loss at Ka-band. SIWs and SSPPs exhibit low and high cut-off responses. https://safeersappliancers.shop/product-category/bosch-cma585gs0b-serie-6-900-watt-microwave-built-in-stainless-steel/