A Millimeter Wave High Isolation Resistive Coupler In 45nm RFSOI Technology for Sensing Application

This paper proposes the design and test of a high isolation millimeter wave directional coupler for sensing application. The compact device is fabricated using the 45nm RFSOI technology of Global Foundries. The core size of the coupler is $44 \mu \mathrm{m} \times 34 \mu \mathrm{m}$. An insertion loss close to the expected 3.6 dB and a coupling ratio of about 26 dB within the 40-80 GHz frequency band have been reached. Moreover, the proposed coupler achieved a measured isolation greater than 43 dB at 60 GHz. This performance is particularly mandatory in sensing applications where maintaining the integrity of the measured signal is critical.