Slow-Wave Substrate Integrated Waveguide with Low Loss and Miniaturized Dimensions Using TGV Technology

In this article, a novel slow-wave substrate integrated waveguide (SW-SIW) with low loss and miniaturized dimensions is presented. The SW effect is obtained by incorporating metalized blind vias at the bottom and metalized blind trenches at the top of the single-layer substrate integrated waveguide (SIW). This improved SIW-based topology achieves a dramatic cutoff frequency reduction of 56% with reference to the conventional SIW with the same lateral size. Meanwhile, the proposed topology is realized using laser-induced wet etching (LIWE) through glass vias (TGV) technology. Compared to the printed circuit board (PCB) process, the adopted TGV technology shows the advantages of high precision, high integration, and simplified process. A prototype is fabricated for a proof-of-concept, and the measured results are in good agreement with simulated results indicating the potential of the presented SW-SIW for high-performance millimeter-wave (mm-wave) circuits and systems.