MMIC-to-Dielectric Waveguide Transitions for Glass Packages Above 150 GHz
Thomas Galler, Tobias Chaloun, Winfried Mayer, Kevin Kröhnert, Norbert Ambrosius, Malte Schulz‐Ruhtenberg, Christian Waldschmidt
Abstract
In this work, novel concepts of an electromagnetically coupled transition and a galvanically coupled transition in glass technology are presented. This enables efficient coupling of signals above 150 GHz into a dielectric waveguide (DWG). Laser-induced deep etching (LIDE) technology provides fabrication of glass holes, cavities, and cutouts with a precision suitable for use in highly integrated mm-wave modules. Based on the package concept presented by Galler et al. (2022), this article introduces an ultracompact galvanically isolated transition from monolithic microwave integrated circuit (MMIC) to a mechanically flexible DWG, offering a minimum insertion loss of 2.95 dB. The simple fabrication provides a cost-effective variant for modern system-in-package solutions. In addition, a galvanic through-plating of the glass cover with through-glass vias (TGVs) and a ring slot structure for the excitation of a DWG are presented. Thereby, the integration density and performance can be further increased. A minimum insertion loss of 2.62 dB within a large 1-dB bandwidth of 18 GHz around the operating frequency of 166 GHz is verified by measurement. Both the transitions cover a high integration density, hermetic sealing, and modular use suitable for requirements of today’s modern radar and communication packages.