DOI: 10.1109/TMTT.2026.3669678   IEEEXplore: https://ieeexplore.ieee.org/document/11433001

An integrated dual-directional coupler chip for seamless connection to 1.0- and 0.8-mm coaxial connectors for direct application in next-generation ultrawideband vector network analyzers.

300 MHz to 145 GHz

Copper micro metal additive manufacturing (M-MAM) allows high-order impedance-tapered design and a Swiss-roll shaped folded topology for high density integration without significantly enlarging the chip area. A tailored multilayer process, time-domain optimization of reflection points, and specially engineered interconnection structures between the chip and coaxial connectors combine to accomplish broadband impedance matching.

Next-generation ultrawideband VNA systems.

120 GHz bandwidth with the 1.0 mm connector; 11.5 dB ±0.37 dB flat coupling; >17 dB directivity; >3 dB insertion loss. The coupler is useful down to 10 MHz with a marginal decrease in coupling. 145 GHz bandwidth with the 0.8 mm connector; 11.5 dB ±0.37 dB flat coupling; >14 dB directivity; <3.7 dB insertion loss. This design represents the widest bandwidth reported to date for a packaged dual-directional coupler.