Modeling of Monolithic RF Spiral Transmission-Line Balun

This paper presents models for monolithic RF spiral transmission-line baluns. The balun consists of a pair of spiral couplers fabricated on high resistivity silicon. The lumped-element equivalent models are developed. The second or higher order models are synthesized from the first-order lumped model. All lumped parameters for the models are extracted from the real physical structures. Simulated behaviors from the second-order models are in good agreement to the measured results with approximately 10% difference.