Miniature CMOS Stacked Spiral-Coupled Directional Coupler With -67-dB Isolation and -0.8-dB Insertion Loss

作者：Ye Le^*; Zheng Yongan; Wang Jiayi; Liao Huailin; Huang Ru

来源：IEEE Electron Device Letters, 2012, 33(7): 919-921.

DOI：10.1109/LED.2012.2196749

• CMOS
• directional coupler
• isolation
• stacked spiral-coupled (SSC)

This letter proposes a miniature CMOS stacked spiral-coupled (SSC) directional coupler for a fully integrated CMOS transceiver to isolate the large transmit power from the transmitter to the receiver. It consists of two 90 degrees-rotated center-aligned SSC coils. The path center of one coil is aligned to the gap center of the other coil. The grounded secondary coil plays a role of ground shielding for reducing the insertion loss. Two capacitors are utilized for tuning the center frequency and isolation level. Fabricated in a standard CMOS process, it achieves an isolation of -67 dB, an insertion loss of -0.8 dB, and a coupling of -16.1 dB and only occupies 0.3 x 0.3 mm(2) of silicon area. To the authors' knowledge, this is the first CMOS directional coupler at the UHF band, with the smallest form factor when compared with other implementations of directional couplers.

• 出版日期2012-7
• 单位北京大学