Ultracompact On-Chip Branch Line Coupler Based on Through-Silicon Via Technology

作者：Yue Deng, Fengjuan Wang, Xiangkun Yin, Sa Xiao, Yuan Yang, Ningmei Yu · 发表于：IEEE Transactions on Components Packaging and Manufacturing Technology · 年份：2025 · DOI：10.1109/tcpmt.2025.3533615 · 被引用次数：25 · 研究领域：Photonic and Optical Devices、Silicon and Solar Cell Technologies、Semiconductor materials and interfaces

A compact branch line coupler with lumped elements on silicon substrate is realized by employing through-silicon via (TSV) technology, in which the lumped elements adopt high-density, high-Q3-D solenoid inductors, and double-layer interdigital capacitors, and the proposed coupler is fabricated and measured. The results show that the return loss of the coupler is less than -19.7 dB, the isolation is less than -15.2 dB at 4.7–5.3 GHz, and the phase imbalance within the operating frequency range is within ±1.2°. In addition, the size of the branch line coupler is only$1.2\times 1.36$mm2($0.069\times 0.078~\lambda _{\text {g}}^{2}$).