FMR Effects on Integrated Ferromagnetic Thin-film RF Inductors

Ferromagnetic inductors with various geometries and permalloy thin film patterns were fabricated on the standard silicon substrate with a fully CMOS compatible process. The ferromagnetic resonance effects on the inductors were studied with the applied magnetic fields in different orientations. It showed that with the properly applied magnetic field, the ferromagnetic resonance for the patterned permalloy thin films can be pushed higher and the maximum quality factor for the ferromagnetic inductors can be improved. However, because the relative permeability decreases with increasing applied field, the trade-off between the effective inductance and the quality factor needs to be optimized for the practical designs.

Power Distribution Analysis of Multi-Layer Substrates With Power Decoupling Capacitors

This paper describes power distribution design and analysis for multi-layer LTCC (low temperature co-fired ceramic) substrates intended for broadband digital applications. Both land side discrete capacitor (LSC, i.e. mounted on the bottom) and top side discrete capacitor (TSC, i.e. mounted on the top or the same side as the active device) configurations were compared in terms of impedance characteristics up to 3 GHz, with respect to different port locations for the active device. Full-wave electromagnetic modeling was carried out to study the impedance characteristics and good correlation with vector network analyzer measurements was achieved. At lower frequencies well below the self-resonant frequency of the intrinsic power plane, the effective impedance is dominated by the series effective inductance. It was observed that the LSC configuration achieves lower impedance due to a reduced series effective inductance since the TSC configuration results in a longer low frequency impedance path. At higher frequencies, however, the LSC configuration actually results in an impedance peak at a lower frequency due to the parallel resonance attributed to the power planes.

Novel Two-Dimensional (2-D) Defected Ground Array for Planar Circuits

This paper presents a novel two-dimensional (2-D) defected ground array (DGA) for planar circuits, which has horizontal and vertical periodicities of defect structure. The defected unit cell of DGA is composed of a Sierpinski carpet structure to improve the effective inductance. Measurements show that the proposed DGA provides steeper cutoff characteristics, lower cutoff frequency, and higher slow-wave factors than the conventional periodic defected ground structure in the same occupied surface.