Low‐loss broadband (DC to 220 GHz) S‐CPW to S‐CPS transition for S‐CPS coplanar probing

Abdelhalim Saadi (1) , Marc Margalef-Rovira (2) , L. Vincent (3) , Sylvie Lepilliet (4) , Christophe Gaquière (4, 5) , Philippe Ferrari (1)

1 RFIC-Lab - Laboratoire de Radio-Fréquence et d'Intégration de Circuits
2 TIMA - Techniques de l'Informatique et de la Microélectronique pour l'Architecture des systèmes intégrés
3 CEA-DES (ex-DEN) - CEA-Direction des Energies (ex-Direction de l'Energie Nucléaire)
4 IEMN - Institut d’Électronique, de Microélectronique et de Nanotechnologie - UMR 8520
5 PUISSANCE - IEMN - Puissance - IEMN

The practical issue of probing coplanar stripline (CPS) structures is addressed in this Letter. A compact slow-wave coplanar waveguide (S-CPW) to slow-wave CPS (S-CPS) transition was designed and fabricated in a 55 nm BiCMOS process of STMicroelectronics. The signal strips of the slow-wave CPW and slow-wave CPS have been directly connected while the ground strips have been tied together through combination of transmission lines laid out on the top metal layer of the back-end-of-line of the technology. Thanks to its flexibility, the proposed transition can be resized to match with a wide range of slow-wave CPS slot. Tested from DC to 220 GHz, the back-to-back transition structure showed insertion loss lower than 1.4 dB and return loss better than 15 dB, respectively. To the best of author's knowledge, it is the first integrated slow-wave CPW/CPS transition introduced within the mentioned mm-wave band.

Domaines: Sciences de l'ingénieur [physics]

Abdelhalim Saadi, Marc Margalef-Rovira, L. Vincent, Sylvie Lepilliet, Christophe Gaquière, et al.. Low‐loss broadband (DC to 220 GHz) S‐CPW to S‐CPS transition for S‐CPS coplanar probing. Electronics Letters, 2019, 55 (21), pp.1137-1139. ⟨10.1049/el.2019.2377⟩. ⟨hal-03133346⟩