| Based on its performance capabilities, low cost, and capacity for high-integration, silicon-germanium (SiGe) heterojunction bipolar transistor (HBT) BiCMOS technology has established itself as strong technology contender for a host of circuit applications including analog, mixed-signal, RF and millimeter-wave. However, as operating frequencies for wireless applications are pushed upward in the spectrum, SiGe HBT technologies face significant challenges at the transistor-level as operating voltage limits decrease and performance requirements increase. This work will investigate operational voltage constraints and dynamic range for state-of-the-art SiGe HBTs.;The fundamental limits related to avalanche breakdown and linearity performance of SiGe HBTs will be comprehensively examined at the transistor-level across multiple technology generations, and the corresponding circuit-level impacts for high-frequency transceiver blocks will be evaluated. The bias dependencies of avalanche breakdown instabilities will be analyzed, and performance and reliability of SiGe HBTs under aggressive bias conditions will be studied. Breakdown instabilities will also be investigated in the context of extreme environments. Linearity will be studied across bias and geometry at the transistor-level to understand the limits and trade-offs of achieving high dynamic range performance in SiGe HBTs. Simple expressions for common-base linearity will be derived from analysis of the SiGe HBT using Volterra series. Based on these studies, circuit-level design techniques for robust performance and enhanced dynamic range will be proposed, and new RF circuit designs using these techniques will be presented.;The following items summarize new contributions to the field made by this work. (1) The first-ever comprehensive analysis of the effects of scaling and bias on operating voltage constraints in advanced SiGe HBTs [20]. (2) Novel analysis of factors contributing to common-base avalanche instabilities in SiGe HBTs [21]. (3) An investigation of operating voltage constraints for SiGe HBTs operating in extreme environments [22], [23]. (4) Analysis of large-signal RF performance, linearity, and reliability of SiGe HBTs under aggressive bias conditions [24]. (5) Novel investigation of large-signal RF operating limits for SiGe HBTs, with new expressions describing the RF safe-operating area [25]. (6) Investigation of common-base intermodulation distortion with new expressions for linearity performance derived from Volterra series analysis [26]. (7) Novel circuit designs, including an aggressive-cascode power amplifier for improved power density, and a low-noise amplifier with enhanced dynamic range performance [27]. |
