Design of RF filters using silicon integrated passive components

The paper discusses the design and characterization of RF filters in Freescale's 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.