A Compensated Finite-Ground Elevated Coplanar Waveguide Interconnect Strategy for InP Based Integrated Circuits Above 100 GHz

• Published in: 2024 19th European Microwave Integrated Circuits Conference (EuMIC) pp. 98 - 101
• Main Authors: Johansen, T. K., Hersent, R., Nodjiadjim, V., Riet, M., Mismer, C., Ardouin, B.
• Format: Conference Proceeding
• Language: English
• Published: European Microwave Association (EuMA) 23-09-2024
• Subjects: Bridge circuits; Coplanar waveguides; D-band; III-V semiconductor materials; Indium phosphide; InP; Insertion loss; Integrated circuit interconnections; Loss measurement; millimeter-wave integrated circuits; Propagation losses; Transmission line measurements; Waveguide discontinuities
• DOI: 10.23919/EuMIC61603.2024.10732365

In this paper, a low-loss interconnect strategy for InP integrated circuits operating above 100 GHz is proposed. The interconnect strategy is based upon finite-ground elevated coplanar waveguide (FG-ECPW) structures and requires no through-substrate vias (TSVs) or backside processing. To minimize the reflection losses at the FG-ECPW discontinuities, the ground bridge parasitics are compensated leading to a seamless transmission characteristic through FG-ECPW structures such as Tee-junctions, bends and crosses. The compensated FG-ECPW interconnects have been implemented in a high-speed, mixed-signal InP DHBT technology from III-V Lab. A compensated FG-ECPW meandered line with an accumulated length of 1.65 mm shows a resonance free, single-mode transmission characteristic with an average insertion loss of 2.4 dB in the full D-band from 110-170 GHz. The measured improvement in insertion loss is 3.7 dB at 170 GHz over a similar noncompensated FG-ECPW meandered line.