Low-cost compact spiral inductor resonator filters for system-in-a-package

In this paper, compact resonator filters embedded in package substrate are proposed using compact spiral resonators. The design is based on the self-resonance frequency of the spiral inductors and electromagnetic coupling effects among resonators. The filters were built and measurement results have good agreement with the simulation data. The proposed filter design technique is generalized and can be implemented in different multilayer arrangements. These new compact inductor resonator filters exhibit a significant size reduction compared to existing distributed filter topologies. The inductor resonator filter designs are based on full-wave electromagnetic analysis. A lumped element equivalent circuit based on the simulated data of the filter is also derived for integration in SPICE-type simulators. The compactness of the newly developed bandpass filter makes the design and integration of bandpass filters attractive for further development and applications in system-in-a-package (SIP) applications.