Michael F. Petras

Magnetic properties of metallic ferromagnetic nanoparticle composites

Magnetic properties of nanoparticle composites, consisting of aligned ferromagnetic nanoparticles embedded in a nonmagnetic matrix, have been determined using a model based on phenomenological approaches. Input materials parameters for this model include the saturation magnetization (Ms), the crystal anisotropy field (Hk), a damping parameter (α) that describes the magnetic losses in the particles, and the conductivity (σ) of the particles; all particles are assumed to have identical properties. Control of the physical characteristics of the composite system—such as the particle size, shape, volume fraction, and orientation—is necessary in order to achieve optimal magnetic properties (e.g., the magnetic permeability) at GHz frequencies. The degree to which the physical attributes need to be controlled has been determined by analysis of the ferromagnetic resonance (FMR) and eddy current losses at varying particle volume fractions. Composites with approximately spherical particles with radii smaller than 10...

Tantalum nitride thin film resistors for integration into copper metallization based RF-CMOS and BiCMOS technology platforms

Metal thin film resistors have been integrated into a damascene-copper multilayer metallization system for mixed-signal BiCMOS technology platforms. The thin film process can be adjusted to achieve resistors with very low temperature coefficients, high linearity, low noise, and improved matching as compared to resistors based on implanted silicon or polysilicon processing. In addition, improvement in terms of good RF performance was observed.

Design of RF filters using silicon integrated passive components

The paper discusses the design and characterization of RF filters in Freescales 0.4 micron SiGe BiCMOS process. An integration scheme for bandpass filters on a standard silicon substrate using monolithic transformers is presented. A 1.9 GHz filter using a single transformer as well as its dual, where the transformer is replaced by three inductors, is fabricated and measured up to 10 GHz. It is demonstrated that the transformer-based filter occupies less chip area than its inductor-based dual, with similar performance. In addition, results of a 1.7 GHz lowpass (harmonic) filter that exclusively uses high-quality factor (Q) inductors and metal-insulator-metal (MIM) capacitors, designed using scalable models is presented. First pass results show very good agreement between models and measurement.

Integrated Passives for Commercial Wireless Applications (Invited Paper)

This paper discusses the modeling, design and performance of inductors and capacitors fabricated in high density interconnect (HDI), low temperature co-fired ceramic (LTCC) and silicon (Si) integrated circuit technologies. Scalable models demonstrate the capability of designing LC-based resonators and filters for use in cellular front-end modules. The performance of the circuits is presented along with size comparisons.Copyright