Abstract:
Passive components, including spiral inductors and transformers, fabricated on silicon-based substrates are placing an increasing demand on radio-frequency integrated circuit (RFIC) design. Performance of the RFIC suffers from several non-ideal effects that must be taken into account in order to create a successful design. In particular, monolithic transformers can be a major obstacle for Low-Noise Amplifiers (LNAs), mixers, Voltage Controlled Oscillators (VCOs), and other RFIC circuits. For designers to correctly analyze their designs that include monolithic
transformers, lumped-element models suitable for circuit simulation and design optimization
are required. This thesis work is mainly concerned with the analysis and the methodology of developing a wide-band compact equivalent circuit model for monolithic transformers fabricated on silicon substrates. A new wide-band compact equivalent circuit model for monolithic transformers
fabricated on silicon substrates is presented. The model achieves high wide-band accuracy through the use of the newly developed "Frequency-Dependent Transformer" (FDT) cell, which effectively takes into account the frequency-dependent conductor losses associated with the transformer's windings. A fast extraction technique that allows extraction of the circuit parameters from simulated or measured data is also described. Results are presented for various RFIC transformer configurations including stacked and interleaved topologies. This research provides a complete measurement or simulation-based modeling methodology for four-port transformers on lossy silicon substrates.
