A novel modification to the standard cascode amplifier architecture is presented
in SiGe which allows for an optimal separation of gain and breakdown functions through
the mixed breakdown cascade architecture, opening the door for moderate power
amplifiers in SiGe. Utilizing this technique, a two-stage, high-gain amplifier operating at
X-Band is fabricated and measured. The 20 dB of gain per stage represents the highest
gain at X-Band at the time of publication. Additionally, a near one Watt power amplifier
is designed and fabricated at X-Band, which represents the highest output power in SiGe
at X-Band at time of publication. Related to the power amplifier design, thermal
considerations are also investigated. The validity of utilizing lumped mutual thermal
coupling in SiGe devices is presented. Using this finding, a thermal coupling model and
network which are compliant for use with commonly available HBT models and circuit
simulators is presented. This model and network is used to thermally optimize SiGe PA
cells based upon layout spacing.Ph.D.Committee Member: John Cressler; Committee Member: John Papapolymerou; Committee Member: Joy Laskar; Committee Member: Thomas Morley; Committee Member: William Hun
