Three types of low noise amplifiers operating at 2.4GHz were designed. They are the commonly used single-ended and differential amplifiers as well as a new quasi-differential amplifier. The substrate noise injected into these amplifiers is examined for both heavily and lightly doped CMOS substrates. For the single-ended amplifier the noise...
The design of a preamplifier for use with a piezoelectric transducer is generally approached from the point of view that an extremely high input impedance is required to obtain low frequency response. However, piezoelectric transducers are essentially charge generators and this fact may be utilized in designing preamplifiers to be...
Conventional bi-polar transistors are inherently low input
impedance devices. Transistor amplifiers have been designed
which will present high input impedance, but the frequency response
is limited to low frequencies, hundreds of kilocycles.
This thesis investigates both field effect transistors and
positive feedback as applied to high input impedance wide band...
New amplifier architectures are presented using non-traditional methods of biasing. Time-based dynamic biasing and signal-based dynamic biasing are discussed in the context of new architectures. This includes a new form of ring amplification with a dynamic deadzone, allowing for a structure whose coarse path does not consume static power.
This thesis deals with the output statistics of nonlinear devices.
It develops the classical output autocorrelation function in two dimensions
and extends the theory to three and four dimensions. Closed
form solutions for the output correlation function in two and three
dimensions are given for the full- and half-wave rectifier...
Supply noise is one of the major considerations in almost all analog building blocks. In the past, adequate supply rejection is usually achieved with circuit isolation or excess capacitive coupling. However, this brute force method requires large silicon area and degrades feedback bandwidth. In this study, a method of enhancing...
Wideband tunnel-diode amplifiers using common-base
transistor stages for isolation were investigated for
stability criteria, frequency response, and the effects
of temperature and voltage supply fluctuations. For the
first time the full frequency spectrum of a tunnel-diode,
from d-c to the gigahertz (GHz) range, was able to be
utilized in an...
Three synthesis methods for the realization of the
voltage transfer function by means of RC elements and
three different active devices are presented. These
three devices are a high-gain amplifier, a voltage controlled
voltage source (VCVS) and a negative immittance
converter (NIC). The VCVS and NIC as well as the...
It is often necessary in communication systems to detect very
small signals that are buried in noise. One device used to accomplish
this is a lock-in amplifier. Initially the theory of operation is considered.
Then the circuit design of a low cost lock-in amplifier is
given. The amplifier, employing linear...
This thesis discusses the design and evaluation of an instrument
that can detect known signals in noise. This detector uses
two integrators to sense a difference in the received signal between
half-cycles of the known signal.
The detector is useful for sensing signals in the approximate
frequency range of 100...
At frequencies exceeding 1-2 GHz, the substrate network models used in substrate coupling simulation must account for the reactive nature of the substrate. Unlike at low frequencies, where the purely resistive substrate models can be validated through DC resistance measurements, these high-frequency models, comprising reactive components, must be validated through...
Low-dimensional electronic materials offer a platform to observe biological processes with unprecedented spatial and temporal resolution. Carbon nanotubes (CNTs) are the closest physical analog to an ideal 1D system and can be scaled and integrated into multiplexed electronic circuitry. The molecular structure of a CNT is also biocompatible, making them...
An analysis of substrate noise coupling in mixed-signal circuits has been performed in the TSMC 0.25 [mu]m lightly doped and heavily doped CMOS processes. Methods to minimize noise coupling in both the chip design and board design phases are presented along with techniques for accurate circuit simulation of noise coupling....
Periodic signals hidden in noise may be detected by using
correlation techniques This thesis presents a study of how
correlation is approximated statistically, and carried out electronically.
The ability to detect periodic signals in noise, using correlation,
is justified mathematically in the first portion of the thesis.
The discussion is...
This thesis presents distinctly different methods of accurately predicting phase noise and absolute jitter in ring oscillators. The phase noise prediction methods are the commercially available SpectreRF and isf_tool, a simulator developed in this work from the Hajimiri and Lee theory of phase noise. Absolute jitter due to deterministic supply...
Digital phase-locked loops (PLLs) have been receiving increasing attention recently due to their ease of integration, scalability and performance comparable to their analog counterparts. In digital PLLs, increased resolution in time-to-digital conversion is desirable for improved noise performance. This work describes the design and simulation of a stochastic time-to-digital converter...
A digital implementation of a PLL has several advantages compared to its
analog counterpart. These include easy scalability with process shrink, elimination
of the noise susceptible analog control for a voltage controlled oscillator (VCO) and
the inherent noise immunity of digital circuits. Several recent digital PLL (DPLL)
implementations have achieved...
Advancements in the sophistication and complexity of modern electronic systems are creating a need for highly integrated systems with ever higher operational frequencies. The economical demands of these systems dictate that they be implemented using low cost fabrication technologies, such as digital CMOS. One of the major challenges facing circuit...
This thesis presents methods to reduce the effects of finite opamp DC gain, output voltage swing limitations in opamps, and component mismatches. The primary contribution of this thesis is a new switched-capacitor method named correlated level shifting (CLS). CLS enables true rail-to-rail operation by storing an estimate of the desired...
A new method is presented to compress switching information in large digital circuits. This is combined with an efficient approach of generating the noise signatures of cells in a digital library that results in an accurate and efficient approach for estimating the noise generated in digital circuits. This method provides...
This thesis presents a design-oriented model for lightly doped CMOS substrates. The model predicts the substrate noise coupling between noisy digital and sensitive analog blocks in the early stages of the design. The model scales with the size and separation of these blocks and it is validated with device simulations...
Modern day digital systems employ frequency
synthesizers to provide a common clock to the system.
They are undergoing large scale integration due to which, mitigation
of the effect of noise on power supply has become a major design consideration
in clocking circuits. Rapid scaling of CMOS technology mandates the
design...
Various applications like wireless UWB communication, fast data acquisition systems and digital storage oscilloscopes needs ADCs with instantaneous input signal bandwidth from 0.1-40 GigaHertz range with 6-10 bits of resolution -- a challenging task and an impressive goal to achieve. Flash ADCs have been conventionally employed to achieve these goals...
With edge rates of high speed digital devices pushing into the sub-nano second
range, interconnections with the associated packages play a major role in determining
the speed, size and performance of digital circuits and systems. The purpose of this
study is to develop experimental techniques based on time domain peeling...
This dissertation presents a dual-path 2-0 MASH (Multi-stAge-noise -SHaping) ADC with two verified digital corrections of DAC mismatch error and quantization noise leakage. By using these two techniques, the requirements for the analog circuits are greatly relaxed. The dual-path structure generates two outputs, one only composed of conversion errors, the...
This research work focuses on the mechanism of 1/f noise in GaAs
resistors on semi-insulating substrates and 1/f noise due to temperature
fluctuations in heat conduction in resistors, diodes, and bipolar transistors. The
goal of this research is to generate accurate models to explain physical origin of 1/f
noise in...
A Z-parameter based macromodel for characterizing the substrate noise coupling in a lightly doped substrate at low frequencies has been developed. The model is scalable with contact geometries and separation. The cross-coupling impedance between two contacts is modeled using an improved geometric mean distance formulation. This approach obviates the need...
This thesis presents a Z-parameter based model to predict the substratenoise coupling between two contacts in a heavily doped substrate for frequenciesless than 2 GHz. The empirical model is scalable with contact size and spacingsbetween the contacts and model parameters can be readily extracted from simu-lated or measured data. The...
An analysis that accounts for the effect of standard electrostatic discharge (ESD) structures on critical LNA specifications of noise figure, input matching and gain is presented. It is shown that the ESD structures degrade LNA performance particularly for higher frequency applications. Two LNAs, one with ESD protection and one without,...
High performance multi-cell delta-sigma modulators are a preferred choice in applications which require programmability. Multi-cell delta-sigma modulators with M unit cells provide 10log10(M) SQNR improvement for the same thermal noise and bias power due to the uncorrelated quantization noises of the M unit ADCs. This concept is used in this...
Full integration of CMOS low noise amplifiers (LNA) presents a challenge for low
cost CMOS receiver systems. A critical problem faced in the design of an RF CMOS LNA
is the inaccurate high-frequency noise model of the MOSFET implemented in circuit
simulators such as SPICE. Silicon-based monolithic inductors are another...
The purpose of this thesis is to apply the Canonical Correlation
Analysis (CCA) which belongs to the parametric methods for power
spectral estimation in the environments of either white noise or
colored noise. It is shown that optimal state space variables
belong to the range space of the canonical vectors...
The tremendous growth of wireless and mobile communications has resulted in placing of stringent requirements on the channel spacing and, by implication, on the phase noise of oscillators, typically mandating the use of passive LC oscillators with high quality factor (Q). However the trend towards large-scale integration and low cost...
This thesis presents a systematic top-down methodology for simulating a phase-locked loop using a macro model in Verilog-A. The macromodel has been used to evaluate the jitter due to supply noise, thermal noise, and ground bounce. The noise simulation with the behavioral model is roughly 310 times faster (best case)...
Previous work at Stanford University has demonstrated that inductance in the
substrate connection is the principal problem underlying the coupling of digital
switching noise into analog circuits. The low impedance substrate can be treated
as a single node over a local area. Switching in the digital circuits produces
current transients...
This thesis examines substrate noise coupling for NMOS transistors in heavily doped substrates. The study begins with the analysis of an NMOS transistor switching noise in a digital inverter at the device level. A resistive substrate network for the NMOS transistor is proposed and verified. Coupling between N+- P+ contacts...
There is a large and growing market for portable consumer audio products
with very small size. As the size of these products is reduced, the area occupied
by batteries becomes significant and hence limits the number of batteries to one.
In order to build such small products, high levels of...
Low noise oscillators are universally needed in digital systems for clock generation and synchronization, and in radio-frequency communication front-ends for frequency up- and down-conversion. Noise in oscillators results in timing jitter, and limits the clock frequency of digital systems. In radio-frequency communication systems, phase noise in oscillators lowers the signal-to-noise...
This work presents the design and implementation of a low power phased-array receiver frontend at 28 GHz in 65 nm CMOS. The frontend incorporates a low- power low-noise amplifier(LNA) and a passive reflection-type phase shifter (RTPS) capable of providing 360° phase shift with 5-bit phase resolution and low loss variation....
A comprehensive and scalable solution for high-performance switched capacitor amplification is presented. Central to this discussion is the concept of ring amplification. A ring amplifier is a small modular amplifier derived from a ring oscillator that naturally embodies all the essential elements of scalability. It can amplify with accurate rail-to-rail...
In modern digital communication systems, error correction codes (ECC) are widely used and play an important role. The main effect of ECCs is to reduce the transmission error caused by channel noise, thereby protecting data and increasing the quality of information transmission. In addition, high spectral efficiency is desired in...
Desire for low-power, high performance computing has been at core of the symbiotic union between digital circuits and CMOS scaling. While digital circuit performance improves with device scaling, analog circuits have not gained these benefits. As a result, it has become necessary to leverage increased digital circuit performance to mitigate...
This dissertation presents an incremental analog-to-digital converter (ADC) with digital digital-to-analog converter (DAC) mismatch correction. A theoretical time-domain analysis technique was developed to predict the noise performance of the incremental ADC, and a new optimization technique was proposed to minimize the output noise.
In the calibration mode, the incremental ADC...
In this thesis, maximum likelihood Doppler frequency estimation and phase noise suppression algorithms for Orthogonal Frequency Division Multiplexing (OFDM) systems are presented. A novel handover decision algorithm for wireless systems, called predictive base station switching (PBSS), is also introduced.
The maximum Doppler Frequency is the ratio of the speed of...
The design of mobile wireless devices has always focused on reducing power, area, and cost. This dissertation proposes two techniques that are leveraged to save power and area and therefore cost. The first techniques reduces the noise in the receiver and results in a relaxed power requirement. The second technique...
For today’s ubiquitous portable devices, innovative integrated circuits with high performance
yet very low power are necessary. As these devices are used to communicate and sense real world signals in the environment, analog-to-digital converters (ADC) and systems are the key interface circuits needed to digitize the sensed information and they...
An enhanced swing differential Colpitts VCO (ESDC-VCO) dramatically improves
the swing of a Colpitts VCO by allowing the signal to swing below ground and above the
supply voltage. Fabricated in a 1P8M 0.13 um CMOS process, the ESDC-VCO operates
at 4.9GHz with a 0.475-V supply and consumes 2.7mW. The measured...
Delta-Sigma (ΔΣ) analog-to-digital converters (ADCs) are traditionally used in high quality audio systems, instrumentation and measurement (I&M) and biomedical devices. With the continued downscaling of CMOS technology, they are becoming popular in wideband applications such as wireless and wired communication systems,high-definition television and radar systems. There are two general realizations...