The object of this thesis is to explore the low-frequency noise (LFN) in silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) and lateral bipolar junction transistors (BJTs). The LFN of SiGe HBTs and lateral BJTs not only determines the lowest detectable signal limit but also induces phase noise in high-frequency applications. Characterizing the LFN behavior and understanding the physical noise mechanism, therefore, are very important to improve the device and circuit performance. The dissertation achieves the object by investigating the LFN of SiGe HBTs and lateral BJTs with different structures for performance optimization and radiation tolerance, as well as by building models that explain the physical mechanism of LFN in these advance bipolar technologies. The scope of this research is separated into two main parts: the LFN of SiGe HBTs; and the LFN of lateral BJTs. The research in the LFN of SiGe HBTs includes investigating the effects of interfacial oxide (IFO), temperature, geometrical dimensions, and proton radiation. It also includes utilizing physical models to probe noise mechanisms. The research in the LFN of lateral BJTs includes exploring the effects of doping and geometrical dimensions. The research work is envisioned to enhance the understanding of LFN in SiGe HBTs and lateral BJTs.

This thesis proposes a modified inductively degenerated common-emitter low-noise amplifier. To add a series-shunt feedback capacitance in series to the base of the cascode transistor for increasing the load impedance of the common-emitter transistor and enhancing the Miller effect, it is applied to improve the circuit¡¦s performance. By thoroughly studying the Miller effect for the input matching, noise, and linearity analysis and derivation of the modified structure, the theoretical analysis and experiments demonstrate the improved linearity and well noise performance. In addition, the proposed method is presented with the good figure of merit. The proposed method is presented in a hybrid circuit with the NEC 2S5010 NPN transistor for 900 MHz applications. It demonstrates that this method improves the linearity and the figure of merit has been increased by 50 to 70 percent. Moreover, the novel low noise amplifier is designed with a 0.35£gm SiGe BiCMOS process supported by the TSMC for 5.7 GHz WLAN band applications. It is found that the circuit has the characteristic of IM3 nonlinearity cancellation because the cascode transistor eliminates the third-order intermodulation genaerated by the common-emitter transistor. This thesis establishes a realizable method for high-linearity low-noise amplifier.

The objective of this thesis is to design RF circuits using silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) for communication system. The packaging effect for the SiGe chip using liquid crystal polymer (LCP) is presented and methodology to derive the model for the package is discussed. Chapter 1, we discuss the overview and benefits of SiGe HBT technology in high frequency circuit design. Chapter 2 presents the methodology of the low noise amplifier (LNA) design and discusses the trade-off between the noise and gain matching. The technique for achieving simultaneous noise and gain matching for the LNA is also presented. Chapter 3 presents an L-band cascaded feedback SiGe low noise amplifier (LNA) design for use in Global Position System (GPS) receivers. Implemented in a 200 GHz SiGe BiCMOS technology, the LNA occupies 1 x 1 millimeter square (including the bondpads). The SiGe LNA exhibits a gain greater than 23 dB from 1.1 to 2.0 GHz, and a noise figure of 2.7 to 3.3 dB from 1.2 to 2.4 GHz. At 1.575 GHz, the 1-dB compression point (P1dB) is 1.73 dBm, with an input third-order intercept point (IIP3) of -3.98 dBm. Lastly, Chapter 4 covers the packaging techniques for the SiGe monolithic integrated circuit (MMIC). We present the modeling of a liquid crystal polymer (LCP) package for use with an X-band SiGe HBT Low Noise Amplifier (LNA). The package consists of a 2 mil LCP laminated over an embedded SiGe LNA, with vias in the LCP serving as interconnects to the LNA bondpads. An accurate model for the packaging interconnects has been developed and verified by comparing to measurement results, and can be used in chip/package co-design.

The objective of this research is to understand the design and performance of state-of-the-art silicon-germanium (SiGe) BiCMOS high-frequency circuits for phased- array radar and wireless communication systems operating in extreme environment conditions. This work investigates the performance of RF circuits over a wide- temperature and exposure to a radiation intensive environment. The design and characterization of a fully integrated transmit/receive (T/R) module and integra- tion onto a multi-element antenna array is presented. In addition, individual circuit blocks are characterized in these extreme environments.

No description available.

Thesis (Ph.D.)--City University of Hong Kong, 2009. / "Submitted to Department of Electronic Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references (leaves 129-134)

Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Cressler, John; Committee Member: Deo, Chaitanya; Committee Member: Doolittle, Alan; Committee Member: Keezer, David; Committee Member: May, Gary; Committee Member: Papapolymerou, John. Part of the SMARTech Electronic Thesis and Dissertation Collection.

published_or_final_version / abstract / toc / Electrical and Electronic Engineering / Master / Master of Philosophy

The objective of the proposed research is to characterize the safe-operating-area of silicon-germanium (SiGe) heterojunction bipolar transistors (HBTs) under radiofrequency (RF) operation and extreme environments. The degradation of SiGe HBTs due to mixed-mode DC and RF stress has been modeled for the first time. State-of-the-art 200 GHz SiGe HBTs were first characterized, and then DC and RF stressed. Excess base leakage current was modeled as a function of the stress current and voltage. This physics-based stress model was then designed as a sub-circuit in Cadence, and incorporated into SiGe power amplifier design to predict the DC and RF stress-induced excess base current. Based on these studies, characterization of RF safe-operating-area for SiGe HBTs using devices and circuits is proposed.

This thesis presents an overview of the simulation, design, and measurement of state-of-the-art Silicon-Germanium Heterojunction Bipolar Transistor (SiGe HBT) variable gain amplifier (VGA). The VGA design trade-off space is presented and methods for achieving an optimized design are discussed. We demonstrate in this thesis that SiGe HBT VGA has the capability to meet the demanding needs for the next generation wireless systems.