A Compact and Layered MMIC Packaging Solution Based on MLCL for Terahertz Applications

This article presents a novel D-band (110–170 GHz) monolithic millimeter-wave integrated circuit (MMIC) packaging solution based on the metallic multilayer coaxial line (MLCL) concept. The proposed MLCL-based packaging is formed by stacking multiple thin metal layers with specific patterns, and is a substrate-less, nonwelded method. A straight MLCL line is manufactured, and the measured results show a transmission loss of 0.027 dB/mm at D-band. A quartz substrate 50-Ω microstrip through-line chip is packaged as a proof-of-concept, and the measured results show that the average insertion loss is 2.34 dB from 110 to 160 GHz. A commercially active D-band low-noise amplifier (LNA) is verified and measured using the proposed concept, and the average gain of this LNA packaging module is 18.91 dB, which exhibits an average in-band loss of 0.69 dB. The proposed MLCL concept could be a suitable candidate for passive components and active components packaging, with potential for low-loss, low-cost, broadband, and highly integrated systems at the terahertz (THz) band.