Contents I. Introduction
In the last few years, groove gap waveguide (GGW) has emerged as an interesting technological solution for the development of advanced RF passive devices [1]. When compared to conventional waveguide, GGW technology offers several benefits for millimeter-wave bandpass filter (BPF) design. First of all, it is well known that the main advantage of GGWs is its potential to circumvent EM-leakage and/or passive-intermodulation issues that can appear when the physical contact between the multiple metal layers is not perfect. This is of paramount importance at high-frequency ranges due to the miniaturization levels required for RF components and their difficulty of assembly. Moreover, other important merits are introduced by the GGW solution, such as the reduction of the mechanical complexity and fabrication costs. Additionally, some initial studies have been already carried out demonstrating that multipactor breakdown power levels can be enhanced in GGW, as well as corona discharge breakdown in inductive-type BPFs [2], [3]. All these features make GGW technology a promising candidate for the development of advanced high-frequency BPFs aimed at high-power-handling scenarios, such as for the RF front-ends of satellite-communication systems.
