Developments of Polymer Microwave Fiber Coupler in eWLB Package for Ultra-High-Speed Communication at D- and Y-Band

Paper in proceeding, 2026

In this paper, we present developments of compact radio-frequency (RF) transitions from an integrated circuit (IC) to polymer microwave fiber (PMF) realized using embedded wafer level ball grid array (eWLB) package at the D- (110–170 GHz) and Y-bands (170–260 GHz). The proposed solution employs a Vivaldi antenna-in-package (AiP) for differential IC interfaces. For single-ended interfaces, a novel inverted Vivaldi antenna is introduced for the first time. The developed PMF couplers exhibit an insertion loss of only 2.5 dB at 140 GHz and 4.5 dB at 240 GHz, opening a path toward the realization of low-cost, high-throughput PMF communication systems.