11.3–13.6-GHz Cryo-CMOS 4P4T RF Switch for Superconducting Quantum Computer at mK Temperature

To address the scalability challenges of traditional series-shunt RF switches, this article presents a scalable multipole N-throw (MPNT) RF switch designed for qubit quantum computers operating at cryogenic temperatures below 1 K. To demonstrate the scalability of the proposed switch in terms of the number of ports, a 4P4T switch with a series-resonance configuration was implemented. The 4P4T switch was fabricated using 65-nm bulk CMOS technology and measured at 300, 77, and 0.6 K using an on-PCB thru-reflect-line (TRL) de-embedding technique. The maximum insertion loss was measured to be 2.5 dB at 600 mK in a dilution refrigerator. The maximum isolation at 600 mK was measured as 25 dB.