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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Sensitivity Analysis and Distortion Decomposition of Mildly Nonlinear Circuits

Zhu, Guoji January 2007 (has links)
Volterra Series (VS) is often used in the analysis of mildly nonlinear circuits. In this approach, nonlinear circuit analysis is converted into the analysis of a series of linear circuits. The main benefit of this approach is that linear circuit analysis is well established and direct frequency domain analysis of a nonlinear circuit becomes possible. Sensitivity analysis is useful in comparing the quality of two designs and the evaluation of gradient, Jacobian or Hessian matrices, in analog Computer Aided Design. This thesis presents, for the first time, the sensitivity analysis of mildly nonlinear circuits in the frequency domain as an extension of the VS approach. To overcome efficiency limitation due to multiple mixing effects, Nonlinear Transfer Matrix (NTM) is introduced. It is the first explicit analytical representation of the complicated multiple mixing effects. The application of NTM in sensitivity analysis is capable of two orders of magnitude speedup. Per-element distortion decomposition determines the contribution towards the total distortion from an individual nonlinearity. It is useful in design optimization, symbolic simplification and nonlinear model reduction. In this thesis, a numerical distortion decomposition technique is introduced which combines the insight of traditional symbolic analysis with the numerical advantages of SPICE like simulators. The use of NTM leads to an efficient implementation. The proposed method greatly extends the size of the circuit and the complexity of the transistor model over what previous approaches could handle. For example, industry standard compact model, such as BSIM3V3 [35] was used for the first time in distortion analysis. The decomposition can be achieved at device, transistor and block level, all with device level accuracy. The theories have been implemented in a computer program and validated on examples. The proposed methods will leverage the performance of present VS based distortion analysis to the next level.
22

CMOS MESFET Cascode Amplifiers for RFIC Applications

January 2019 (has links)
abstract: There is an ever-increasing demand for higher bandwidth and data rate ensuing from exploding number of radio frequency integrated systems and devices. As stated in the Shannon-Hartley theorem, the maximum achievable data rate of a communication channel is linearly proportional to the system bandwidth. This is the main driving force behind pushing wireless systems towards millimeter-wave frequency range, where larger bandwidth is available at a higher carrier frequency. Observing the Moor’s law, highly scaled complementary metal–oxide–semiconductor (CMOS) technologies provide fast transistors with a high unity power gain frequency which enables operating at millimeter-wave frequency range. CMOS is the compelling choice for digital and signal processing modules which concurrently offers high computation speed, low power consumption, and mass integration at a high manufacturing yield. One of the main shortcomings of the sub-micron CMOS technologies is the low breakdown voltage of the transistors that limits the dynamic range of the radio frequency (RF) power blocks, especially with the power amplifiers. Low voltage swing restricts the achievable output power which translates into low signal to noise ratio and degraded linearity. Extensive research has been done on proposing new design and IC fabrication techniques with the goal of generating higher output power in CMOS technology. The prominent drawbacks of these solutions are an increased die area, higher cost per design, and lower overall efficiency due to lossy passive components. In this dissertation, CMOS compatible metal–semiconductor field-effect transistor (MESFETs) are utilized to put forward a new solution to enhance the power amplifier’s breakdown voltage, gain and maximum output power. Requiring no change to the conventional CMOS process flow, this low cost approach allows direct incorporation of high voltage power MESFETs into silicon. High voltage MESFETs were employed in a cascode structure to push the amplifier’s cutoff frequency and unity power gain frequency to the 5G and K-band frequency range. This dissertation begins with CMOS compatible MESFET modeling and fabrication steps, and culminates in the discussion of amplifier design and optimization methodology, parasitic de-embedding steps, simulation and measurement results, and high resistivity RF substrate characterization. / Dissertation/Thesis / Doctoral Dissertation Electrical Engineering 2019
23

CMOS RFIC Design and Implementation for DVB-H Zero-IF Tuner Applications

Lian, Yi-jie 16 August 2007 (has links)
This thesis is composed of three parts. The first part surveys the literature on RF architecture and semiconductor process technology in the DVB-H tuner applications. The RFIC design considerations are also discussed. In the second part, the DVB-H tuner RFIC design using TSMC 0.18£gm RF CMOS technology is presented. Discussions between simulated and measured results of each circuit stage are also included. In the third part, the RFIC testing results for CW and DVB-H input signals are demonstrated. For a QPSK signal with 8MHz bandwidth and 7/8 code rate, the sensitivity of the RFIC can reach -87dBm. The adjacent channel protection ratio can meet the specification. The chip power consumption is 70.2mW, and the chip size is 1.96 mm2.
24

Design of microwave low-noise amplifiers in a SiGe BiCMOS process / Design av mikrovågs lågbrusförstärkare i en SiGe BiCMOS process

Hansson, Martin January 2003 (has links)
In this thesis, three different types of low-noise amplifiers (LNA’s) have been designed using a 0.25 mm SiGe BiCMOS process. Firstly, a single-stage amplifier has been designed with 11 dB gain and 3.7 dB noise figure at 8 GHz. Secondly, a cascode two-stage LNA with 16 dB gain and 3.8 dB noise figure at 8 GHz is also described. Finally, a cascade two-stage LNA with a wide-band RF performance (a gain larger than unity between 2-17 GHz and a noise figure below 5 dB between 1.7 GHz and 12 GHz) is presented. These SiGe BiCMOS LNA’s could for example be used in the microwave receivers modules of advanced phased array antennas, potentially making those more cost- effective and also more compact in size in the future. All LNA designs presented in this report have been implemented with circuit layouts and validated through simulations using Cadence RF Spectre.
25

CMOS integrated LC Q-enhanced RF filters for wireless receivers

Gee, Wesley Albert 15 July 2005 (has links)
In wireless transceiver circuits some of the most prevalent required off-chip components are discrete filters. These components are generally implemented with surface acoustic wave (SAW) or ceramic components. These devices are used in the receiver section for discrimination of incoming radio frequency (RF) signals as well as downconverted intermediate frequency (IF) signals. Presently, with the growing demand for multi-functional wireless consumer devices, the need for full integration of RF and logic circuits in wireless communications systems is becoming increasingly evident. If integrated RF filters with acceptable electrical characteristics could be realized, this might reduce or eliminate the currently required off-chip filters, prospectively decreasing the complexity, size, and cost of future wireless transceiver circuits and systems. The objective of the present research effort is to implement an integrated Q-enhanced LC bandpass filter in a prospective receiver front-end RF amplifier using the passive and active components available in a standard digital complementary metal-oxide semiconductor (CMOS) process. CMOS is the standard design medium for digital circuitry, and with the increased unity gain or transit frequency (fT) values that accompany steadily shrinking CMOS device sizes, the implementation of gigahertz frequency communications circuits in this medium is increasingly feasible. The circuit design specifically investigated in this work introduces a loss-compensated second-order gigahertz range bandpass filter implemented in a 0.18 쭠digital CMOS process provided by National Semiconductor. This filter incorporates a unique design technique that provides improvements in filter linearity through an independently variable bias level shifting method, while also facilitating prospective single-to-differential signal conversion. One distinctive characteristic of the investigated circuit, in comparison to other RF integrated filter work, is the implementation of a novel integrated transformer feedback method that facilitates magnetically coupled loss-restoration and subsequent filter Q-enhancement. Additionally, this loss restoration method is achieved using a single transistor, in contrast to the multi-transistor cross-coupled transconductor Q-enhancement technique commonly implemented in other previous and current integrated RF filter research.
26

A Highly Linear Broadband LNA

Park, Joung Won 2009 August 1900 (has links)
In this work, a highly linear broadband Low Noise Amplifier (LNA) is presented. The linearity issue in broadband Radio Frequency (RF) front-end is introduced, followed by an analysis of the specifications and requirements of a broadband LNA through consideration of broadband, multi-standard front-end design. Metal-Oxide- Semiconductor Field-Effect Transistor (MOSFET) non-linearity characteristics cause linearity problems in the RF front-end system. To solve this problem, feedback and the Derivative Superposition Method linearized MOSFET. In this work, novel linearization approaches such as the constant current biasing and the Derivative Superposition Method using a triode region transistor improve linearization stability against Process, Supply Voltage, and Temperature (PVT) variations and increase high power input capability. After analyzing and designing a resistive feedback LNA, novel linearization methods were applied. A highly linear broadband LNA is designed and simulated in 65nm CMOS technology. Simulation results including PVT variation and the Monte Carlo simulation are presented. We obtained -10dB S11, 9.77dB S21, and 4.63dB Noise Figure with IIP3 of 19.18dBm for the designed LNA.
27

Design of microwave low-noise amplifiers in a SiGe BiCMOS process / Design av mikrovågs lågbrusförstärkare i en SiGe BiCMOS process

Hansson, Martin January 2003 (has links)
<p>In this thesis, three different types of low-noise amplifiers (LNA’s) have been designed using a 0.25 mm SiGe BiCMOS process. Firstly, a single-stage amplifier has been designed with 11 dB gain and 3.7 dB noise figure at 8 GHz. Secondly, a cascode two-stage LNA with 16 dB gain and 3.8 dB noise figure at 8 GHz is also described. Finally, a cascade two-stage LNA with a wide-band RF performance (a gain larger than unity between 2-17 GHz and a noise figure below 5 dB between 1.7 GHz and 12 GHz) is presented. </p><p>These SiGe BiCMOS LNA’s could for example be used in the microwave receivers modules of advanced phased array antennas, potentially making those more cost- effective and also more compact in size in the future. </p><p>All LNA designs presented in this report have been implemented with circuit layouts and validated through simulations using Cadence RF Spectre.</p>
28

Millimeter-wave and sub-terahertz on-chip antennas, arrays, propagation, and radiation pattern measurements

Gutierrez, Felix, active 2013 10 February 2014 (has links)
This dissertation focuses on the development of next generation wireless communications at millimeter-wave and sub-terahertz frequencies. As wireless providers experience a bandwidth shortage and cellular subscribers demand faster data rates and more reliable service, a push towards unused carriers fre- quencies such as 28 GHz, 60 GHz, and 180 GHz will alleviate network conges- tion while simultaneously providing massive bandwidths to consumers. This dissertation summarizes research in understanding millimeter-wave wireless propagation, the design and fabrication of millimeter-wave and sub-terahertz on-chip antenna arrays on an integrated circuit semiconductor process, and the accurate measurement of on-chip antenna radiation patterns in a wafer probe station environment. / text
29

Study Of Nanoscale Cmos Device And Circuit Reliability

Yu, Chuanzhao 01 January 2006 (has links)
The development of semiconductor technology has led to the significant scaling of the transistor dimensions -The transistor gate length drops down to tens of nanometers and the gate oxide thickness to 1 nm. In the future several years, the deep submicron devices will dominate the semiconductor industry for the high transistor density and the corresponding performance enhancement. For these devices, the reliability issues are the first concern for the commercialization. The major reliability issues caused by voltage and/or temperature stress are gate oxide breakdown (BD), hot carrier effects (HCs), and negative bias temperature instability (NBTI). They become even more important for the nanoscale CMOS devices, because of the high electrical field due to the small device size and high temperature due to the high transistor densities and high-speed performances. This dissertation focuses on the study of voltage and temperature stress-induced reliability issues in nanoscale CMOS devices and circuits. The physical mechanisms for BD, HCs, and NBTI have been presented. A practical and accurate equivalent circuit model for nanoscale devices was employed to simulate the RF performance degradation in circuit level. The parameter measurement and model extraction have been addressed. Furthermore, a methodology was developed to predict the HC, TDDB, and NBTI effects on the RF circuits with the nanoscale CMOS. It provides guidance for the reliability considerations of the RF circuit design. The BD, HC, and NBTI effects on digital gates and RF building blocks with the nanoscale devices – low noise amplifier, oscillator, mixer, and power amplifier, have been investigated systematically. The contributions of this dissertation include: It provides a thorough study of the reliability issues caused by voltage and/or temperature stresses on nanoscale devices – from device level to circuit level; The more real voltage stress case – high frequency (900 MHz) dynamic stress, has been first explored and compared with the traditional DC stress; A simple and practical analytical method to predict RF performance degradation due to voltage stress in the nanoscale devices and RF circuits was given based on the normalized parameter degradations in device models. It provides a quick way for the designers to evaluate the performance degradations; Measurement and model extraction technologies, special for the nanoscale MOSFETs with ultra-thin, ultra-leaky gate oxide, were addressed and employed for the model establishments; Using the present existing computer-aided design tools (Cadence, Agilent ADS) with the developed models for performance degradation evaluation due to voltage or/and temperature stress by simulations provides a potential way that industry could use to save tens of millions of dollars annually in testing costs. The world now stands at the threshold of the age of nanotechnology, and scientists and engineers have been exploring here for years. The reliability is the first challenge for the commercialization of the nanoscale CMOS devices, which will be further downscaling into several tens or ten nanometers. The reliability is no longer the post-design evaluation, but the pre-design consideration. The successful and fruitful results of this dissertation, from device level to circuit level, provide not only an insight on how the voltage and/or temperature stress effects on the performances, but also methods and guidance for the designers to achieve more reliable circuits with nanoscale MOSFETs in the future.
30

Built-in-Self-Test and Digital Self-Calibration for Radio Frequency Integrated Circuits

Bou Sleiman, Sleiman 26 September 2011 (has links)
No description available.

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