Miniaturized Wideband Coupler for 60-GHz Band in 65-nm CMOS Technology

摘要

A compact and wideband coupler for the 60-GHz frequency band applications using 65-nm CMOS technology is presented. By meandering the coupled line, a miniaturized coupler can be obtained. The proposed coupler achieves a measured insertion loss between the input port and the through port (${S}_{21}$) of 6.3 dB and between the input port and the coupled port (${S}_{31}$) of 5.6 dB at 60 GHz. The measured amplitude imbalance and phase difference are 0.75 dB and 92°, respectively, at 60 GHz. Overall, the proposed coupler can achieve a measured amplitude imbalance of <1 dB, phase imbalance of <4°, return loss, and isolation better than 13 and 20 dB, respectively, from 50 to 67 GHz. In addition, the proposed coupler occupies a core area of only$156,,mu ext{m},,imes 157,,mu ext{m}$(0.024 mm^2).