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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.
91

Design of a Direct-conversion Radio Receiver Front-end in CMOS Technology

Erixon, Mats January 2002 (has links)
In this Master's thesis, a direct-conversion receiver front-end has been designed in a 0.18um CMOS technology. Direct-conversion receivers (DCR) have obvious advantages over the heterodyne counterpart. Since the intermediate frequency (IF) is zero, the problem of image is circumvented. As a result, no front-end image reject filter is required and the channel selection requires only a low-pass filter, which makes it easy to integrate directly on chip. However, the DCR also suffers from several drawbacks such as extreme sensitivity to DC offsets, 1/f noise, local oscillator (LO) leakage/radiation, front-end nonlinearity and I/Q mismatch. This implies very high demands on the DCR front-end. The front-end comprises a low-noise amplifier (LNA) and a mixer. Different LNA and mixer architectures has been studied and from the mentioned inherited problems with direct conversion, one proposal for a solution is a differential source degenerated LNA and a differential harmonic mixer, which has been designed and simulated. The LNA has a gain of 12dB, a noise figure of 3.6dB and provides a return loss better than -15dB. The overall noise figure of the signal path is 8dB and the overall IIP3 and IIP2 is -12dBm and 31dBm, respectively.
92

Design and Evaluation of an Ultra-Low PowerLow Noise Amplifier LNA

yasami, saeed January 2009 (has links)
This master thesis deals with the study of ultra low power Low Noise Amplifier (LNA) for use inmedical implant device. Usually, low power consumption is required for a long battery lifetime andlonger operation. The target technology is 90nm CMOS process.First basic principle of LNA is discussed. Then based on a literature review of LNA design, theproposed LNA is presented in sub-threshold region which reduce power consumption through scalingthe supply voltage and through scaling current.The circuit implementation and simulations is presented to testify the performance of LNA .Besides thepower consumption simulated under the typical supply voltage (1V), it is also measured under someother low supply voltages (down to 0.5V) to investigate the minimum power consumption and theminimum noise figure. Evaluation results show that at a supply voltage of 1V the LNA performs a totalpower consumption of 20mW and a noise of 1dB. Proper performance is achieved with a current ofdown to 200uA and supply voltage of down to 0.45V, and a total power consumption of 200uW
93

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.
94

Design of Baluns and Low Noise Amplifiers in Integrated Mixed-Signal Organic Substrates

Govind, Vinu 19 July 2005 (has links)
The integration of mixed-signal systems has long been a problem in the semiconductor industry. CMOS System-on-Chip (SOC), the traditional means for integration, fails mixed-signal systems on two fronts; the lack of on-chip passives with high quality (Q) factors inhibits the design of completely integrated wireless circuits, and the noise coupling from digital to analog circuitry through the conductive silicon substrate degrades the performance of the analog circuits. Advancements in semiconductor packaging have resulted in a second option for integration, the System-On-Package (SOP) approach. Unlike SOC where the package exists just for the thermal and mechanical protection of the ICs, SOP provides for an increase in the functionality of the IC package by supporting multiple chips and embedded passives. However, integration at the package level also comes with its set of hurdles, with significant research required in areas like design of circuits using embedded passives and isolation of noise between analog and digital sub-systems. A novel multiband balun topology has been developed, providing concurrent operation at multiple frequency bands. The design of compact wideband baluns has been proposed as an extension of this theory. As proof-of-concept devices, both singleband and wideband baluns have been fabricated on Liquid Crystalline Polymer (LCP) based organic substrates. A novel passive-Q based optimization methodology has been developed for chip-package co-design of CMOS Low Noise Amplifiers (LNA). To implement these LNAs in a mixed-signal environment, a novel Electromagnetic Band Gap (EBG) based isolation scheme has also been employed. The key contributions of this work are thus the development of novel RF circuit topologies utilizing embedded passives, and an advancement in the understanding and suppression of signal coupling mechanisms in mixed-signal SOP-based systems. The former will result in compact and highly integrated solutions for RF front-ends, while the latter is expected to have a significant impact in the integration of these communication devices with high performance computing.
95

Design methodologies for built-in testing of integrated RF transceivers with the on-chip loopback technique

Onabajo, Marvin Olufemi 15 May 2009 (has links)
Advances toward increased integration and complexity of radio frequency (RF) andmixed-signal integrated circuits reduce the effectiveness of contemporary testmethodologies and result in a rising cost of testing. The focus in this research is on thecircuit-level implementation of alternative test strategies for integrated wirelesstransceivers with the aim to lower test cost by eliminating the need for expensive RFequipment during production testing.The first circuit proposed in this thesis closes the signal path between the transmitterand receiver sections of integrated transceivers in test mode for bit error rate analysis atlow frequencies. Furthermore, the output power of this on-chip loopback block wasmade variable with the goal to allow gain and 1-dB compression point determination forthe RF front-end circuits with on-chip power detectors. The loopback block is intendedfor transceivers operating in the 1.9-2.4GHz range and it can compensate for transmitterreceiveroffset frequency differences from 40MHz to 200MHz. The measuredattenuation range of the 0.052mm2 loopback circuit in 0.13µm CMOS technology was 26-41dB with continuous control, but post-layout simulation results indicate that theattenuation range can be reduced to 11-27dB via optimizations.Another circuit presented in this thesis is a current generator for built-in testing ofimpedance-matched RF front-end circuits with current injection. Since this circuit hashigh output impedance (>1k up to 2.4GHz), it does not influence the input matchingnetwork of the low-noise amplifier (LNA) under test. A major advantage of the currentinjection method over the typical voltage-mode approach is that the built-in test canexpose fabrication defects in components of the matching network in addition to on-chipdevices. The current generator was employed together with two power detectors in arealization of a built-in test for a LNA with 14% layout area overhead in 0.13µm CMOStechnology (<1.5% for the 0.002mm2 current generator). The post-layout simulationresults showed that the LNA gain (S21) estimation with the external matching networkwas within 3.5% of the actual gain in the presence of process-voltage-temperaturevariations and power detector imprecision.
96

Design of a Direct-conversion Radio Receiver Front-end in CMOS Technology

Erixon, Mats January 2002 (has links)
<p>In this Master's thesis, a direct-conversion receiver front-end has been designed in a 0.18um CMOS technology. </p><p>Direct-conversion receivers (DCR) have obvious advantages over the heterodyne counterpart. Since the intermediate frequency (IF) is zero, the problem of image is circumvented. As a result, no front-end image reject filter is required and the channel selection requires only a low-pass filter, which makes it easy to integrate directly on chip. However, the DCR also suffers from several drawbacks such as extreme sensitivity to DC offsets, 1/f noise, local oscillator (LO) leakage/radiation, front-end nonlinearity and I/Q mismatch. This implies very high demands on the DCR front-end. </p><p>The front-end comprises a low-noise amplifier (LNA) and a mixer. Different LNA and mixer architectures has been studied and from the mentioned inherited problems with direct conversion, one proposal for a solution is a differential source degenerated LNA and a differential harmonic mixer, which has been designed and simulated. </p><p>The LNA has a gain of 12dB, a noise figure of 3.6dB and provides a return loss better than -15dB. The overall noise figure of the signal path is 8dB and the overall IIP3 and IIP2 is -12dBm and 31dBm, respectively.</p>
97

Spin Torque Oscillator Modeling, CMOS Design and STO-CMOS Integration

Chen, Tingsu January 2015 (has links)
Spin torque oscillators (STOs) are microwave oscillators with an attractive blend of features, including a more-than-octave tunability, GHz operating frequencies, nanoscale size, nanosecond switching speed and full compatibility with CMOS technology. Over the past decade, STOs' physical phenomena have been explored to a greater extent, their performance has been further improved, and STOs have already shown great potential for a wide range of applications, from microwave sources and detectors to neuromorphic computing. This thesis is devoted to promoting the STO technology towards its applications, by means of implementing the STO's electrical model, dedicated CMOS integrated circuits (ICs), and STO-CMOS IC integration. An electrical model, which can capture magnetic tunnel junction (MTJ) STO's characteristics, while enabling system- and circuit-level designs and performance evaluations, is of great importance for the development of MTJ STO-based applications. A comprehensive and compact analytical model, which is based on macrospin approximations and can fulfill the aforementioned requirements, is proposed. This model is fully implemented in Verilog-A, and can be used for efficient simulations of various MTJ STOs. Moreover, an accurate phase noise generation approach, which ensures a reliable model, is proposed and successfully used in the Verilog-A model implementation. The model is experimentally validated by three different MTJ STOs under different bias conditions. CMOS circuits, which can enhance the limited output power of MTJ STOs to levels that are required in different applications, are proposed, implemented and tested. A novel balun-low noise amplifier (LNA), which can offer sufficient gain, bandwidth and linearity for MTJ STO-based magnetic field sensing applications, is proposed. Additionally, a wideband amplifier, which can be connected to an MTJ STO to form a highly-tunable microwave oscillator in a phase-locked loop (PLL), is also proposed. The measurement results demonstrate that the proposed circuits can be used to develop MTJ STO-based magnetic field sensing and microwave source applications. The investigation of possible STO-CMOS IC integration approaches demonstrates that the wire-bonding-based integration is the most suitable approach. Therefore, a giant magnetoresistance (GMR) STO is integrated with its dedicated CMOS IC, which provides the necessary functions, using the wire-bonding-based approach. The RF characterization of the integrated GMR STO-CMOS IC system under different magnetic fields and DC currents shows that such an integration can eliminate wave reflections. These findings open the possibility of using GMR STOs in magnetic field sensing and microwave source applications. / <p>QC 20151112</p>
98

Low noise RF CMOS receiver integrated circuits

Woo, Sang Hyun 09 February 2012 (has links)
The objective of this research is to design and implement low-noise wideband RFIC components with CMOS technology for the direct-conversion architecture. This research proposes noise reduction techniques to improve the thermal noise and flicker noise contribution of a low noise amplifier (LNA) and a mixer. Of these techniques, the LNA is found to reduce noise, boost gain, and consume a relatively low amount of power without sacrificing the wideband and linearity advantages of a conventional common gate (CG) topology. The research concludes by investigating the proposed mixer topology, which senses and compensates local oscillator (LO) phase mismatches, the dominant cause of flicker noise.
99

Projeto de um bloco LNA-misturador para radiofrequência em tecnologia CMOS. / A merged RF-CMOS LNA-mixer design in CMOS technology.

Armando Ayala Pabón 15 December 2009 (has links)
Este trabalho apresenta o projeto de um bloco LNA-Misturador dentro de um mesmo circuito integrado para aplicações em um receptor Bluetooth 2;45GHz. Uma estratégia de projeto bem clara, concisa e com uma boa base física e matemática foi desenvolvida para auxiliar o processo de projeto de um bloco LNA-Misturador, composto por um LNA cascode em cascata com um misturador de chaveamento de corrente com entradas simples e degeneração indutiva nas fontes dos estágios de transcondutância. Esta estratégia foi adaptada de trabalhos apresentados na literatura. A estratégia de projeto proposta considera o compromisso entre ruído, linearidade, ganho, dissipação de potência, casamento de impedâncias e isolamento de portas, usando as dimensões dos dispositivos e condições de polarização como variáveis de projeto. Com base nesta estratégia se obteve um bloco LNA-Misturador que atinge algumas especificações propostas. Um bloco LNA-Misturador foi projetado e fabricado em uma tecnologia CMOS 0;35µm para validar a estratégia de projeto proposta. Além disso, para atingir os objetivos, durante o desenvolvimento deste trabalho foi dada atenção especial no projeto dos indutores. Foi projetado, fabricado e medido um chip de teste. Para tal fim foram aplicadas técnicas e estruturas de de-embedding nas medidas para conseguir resultados mais confiáveis. Os resultados experimentais obtidos para os indutores e os resultados preliminares do bloco LNA-Misturador s~ao satisfatórios de acordo com as especificações e os esperados das simulações. No entanto, os indutores integrados degradam significativamente o desempenho do bloco LNA-Misturador. Se forem usados processos de fabricação nos quais os indutores apresentem melhor desempenho, os resultados do bloco LNA-Misturador aplicando a estratégia de projeto desenvolvida neste trabalho podem ser melhorados. Finalmente, é importante ressaltar que a estratégia de projeto proposta neste trabalho já está sendo usada e adaptada em outros projetos com o propósito de melhorar os resultados obtidos, e conseguir auxiliar o processo de projeto deste tipo de blocos. / This work presents a fully integrated LNA-Mixer design for a Bluetooth receiver application at 2:45GHz. A concise design strategy with good physics and mathematics basis was developed to assist the design process of a LNA-Mixer block, formed by a cascode LNA in cascade to a single balanced current commutation Mixer with inductive degeneration. This strategy was adapted from literature and considers the trade-offs between noise, linearity, gain, power dissipation, impedance matching and ports isolation, using the device dimensions and bias conditions as design variables. Based on this strategy, the proposed LNA-Mixer design specifications were achieved. To validate the proposed design strategy, the LNA-Mixer were fabricated in a 0:35µm CMOS process. Furthermore, to achieve the specifications, during the development of this work a special attention to the RF CMOS inductors was given. A test chip was designed, fabricated and measured applying de-embedding structures to obtain more reliable results. The experimental results obtained for the inductors and the preliminary results for the LNA-Mixer are satisfactory compared to the specifications and as expected from simulations. However, the integrated inductors degrade the performance of the block significantly and if a manufacturing process in which the inductor has better performance is used, the resulting LNA-Mixer design applying the strategy developed in this work can be improved. Finally, it is important to highlight that the design strategy proposed in this work is already being used and adapted in other designs in order to improve the results, and to assist the design process of such blocks.
100

Anténa a LNA pro vícepásmový přijímač GNSS / Antenna a LNA for multiband GNSS receiver

Ondráš, Michal January 2019 (has links)
This project describesa microwave antenna for GNSS and low noise amplifier. Mikrostrip antenna is a modern type of antenna. This mikrostrip antenna is Dual – band antenna with circual polarization. The thesis describes how to make anantenna, what a circular polarization is, whata patch antenna is and what GNSS is. Low noise amplifier amplifies the antenna output signal.

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