Design and Implementation of Broadband Hybrid 3-dB Couplers with Silicon-Based IPD Technology

Heterogeneous integration (HI) is a rapidly developing field aimed at achieving high-density integration and miniaturization of devices for complex practical radio frequency (RF) applications. In this study, we present the design and implementation of two 3 dB directional couplers utilizing the broadside-coupling mechanism and silicon-based integrated passive device (IPD) technology. The type A coupler incorporates a defect ground structure (DGS) to enhance coupling, while type B employs wiggly-coupled lines to improve directivity. Measurement results demonstrate that type A achieves <−16.16 dB isolation and <−22.32 dB return loss with a relative bandwidth of 60.96% in the 6.5–12.2 GHz range, while type B achieves <−21.21 dB isolation and <−23.95 dB return loss in the first band at 7–13 GHz, <−22.17 dB isolation and <−19.67 dB return loss in the second band at 28–32.5 GHz, and <−12.79 dB isolation and <−17.02 dB return loss in the third band at 49.5–54.5 GHz. The proposed couplers are well suited for low cost, high performance system-on-package radio frequency front-end circuits in wireless communication systems.