基于MEFAB工艺的平面集成高选择性W波段带通滤波器

In this article, a design method of planar-integrated high-selectivity W-band bandpass filter (BPF) is proposed. A rectangular microcoaxial line (R $\mu $ CL)-to-surface-mounted-technology (SMT) transition and an R $\mu $ CL-to-grounded coplanar waveguide (CPWG) transition are designed for BPF’s planar integration. The two proposed transitions have low insertion loss (IL) in the W band and the R $\mu $ CL-to-CPWG transition has good structural stability by support cube under the inner conductor. The proposed BPF uses a cascaded quadruplet (CQ) topology and has signal interference paths between source and load, which will introduce four transmission zeros (TZs). The proposed transitions and BPFs are fabricated by microstructure electrochemical fabrication (MEFAB) process. The measured results show that the proposed R $\mu $ CL-to-SMT transition and R $\mu $ CL-to-CPWG transition have the IL better than 0.7 and 1.1 dB, respectively. The BPF using the above two transitions has the minimum IL of 1.1 and 1.4 dB, and the size of $2.456\times 2.302\times 0.9$ mm3 and $4.192\times 2.313\times 0.9$ mm3, respectively.