Passive components using quasi-CPW in eWLB package

This paper presents design and simulation of high frequency passive components integrated in the thin-film redistribution layer (RDL) of an embedded wafer level ball grid array (eWLB). The eWLB is an innovative package solution for high frequency and high performance applications. In this work, we investigate the integration of passive components such as antennas, transmission lines and couplers in an eWLB package at the ISM (Industrial, Scientific and Medical) frequency band (61–61.5 GHz). We present simulation results for a new quasi-CPW (coplanar waveguide). This line consists of an elevated center conductor above the ground planes on its both sides and offers a considerably wider range of feasible characteristic impedances compared to classical CPW. The achieved impedances are between 14 Ω and 110 Ω. The obvious advantage of using the new quasi-CPW is simple realization of ground connection. We introduce a rat race coupler designed at 61 GHz using the new quasi-CPW. Finally, we demonstrate the feasibility of an antenna concept in the ISM band. We design a single-ended patch antenna using a new quasi-CPW. The simulated directivity of the antenna is 9dBi.