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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.
31

Integrated Antennas and Active Beamformers Technology for mm-Wave Phased-Array Systems

Biglarbegian, Behzad 26 March 2012 (has links)
In this thesis, based on the indoor channel measurements and ray-tracing modeling for the indoor mm-wave wireless communications, the challenges of the design of the radio in this band is studied. Considering the recently developed standards such as IEEE 802.15.3c, ECMA and WiGig at 60 GHz, the link budget of the system design for different classes of operation is done and the requirement for the antenna and other RF sections are extracted. Based on radiation characteristics of mm-wave and the fundamental limits of low-cost Silicon technology, it is shown that phased-array is the ultimate solution for the radio and physical layer of the mobile millimeter wave multi-Gb/s wireless networks. Different phased-array configurations are studied and a low-cost single-receiver array architecture with RF phase-shifting is proposed. A systematic approach to the analysis of the overall noise-figure of the proposed architecture is presented and the component technical requirements are derived for the system level specifications. The proposed on-chip antennas and antenna-in-packages for various applications are designed and verified by the measurement results. The design of patch antennas on the low-cost RT/Duroid substrate and the slot antennas on the IPD technologies as well as the compact on-chip slot DRA antenna are explained in the antenna design section. The design of reflective-type phase shifters in CMOS and MEMS technologies is explained. Finally, the design details of two developed 60 GHz integrated phased-arrays in CMOS technology are discussed. Front-end circuit blocks such as LNA, continuous passive reflective-type phase shifters, power combiner and variable gain amplifiers are investigated, designed and developed for a 60 GHz phased-array radio in CMOS technology. In the first design, the two-element CMOS phased-array front-ends based on passive phase shifting architecture is proposed and developed. In the second phased-array, the recently developed on-chip dielectric resonator antenna in our group in lower frequency is scaled and integrated with the front-end.
32

Development of microwave/millimeter-wave antennas and passive components on multilayer liquid crystal polymer (LCP) technology

Bairavasubramanian, Ramanan 05 April 2007 (has links)
The investigation of liquid crystal polymer (LCP) technology to function as a low-cost next-generation organic platform for designs up to millimeter-wave frequencies has been performed. Prior to this research, the electrical performance of LCP had been characterized only with the implementation of standard transmission lines and resonators. In this research, a wide variety of passive functions have been developed on LCP technology and characterized for the first time. Specifically, we present the development of patch antenna arrays for remote sensing applications, the performance of compact low-pass and band-pass filters up to millimeter-wave frequencies, and the integration of passive elements for X-band and V-band transceiver systems. First, dual-frequency/dual-polarization antenna arrays have been developed on multilayer LCP technology and have been integrated with micro-electro-mechanical-system (MEMS) switches to achieve real-time polarization reconfigurability. These arrays are conformal, efficient and have all the features desirable for applications that require space deployment. Second, a wide variety of filters with different physical and functional characteristics have been implemented on both single and multilayer LCP technology. These filters can be classified based on the filter type (low-pass/band-pass), the resonators used (single-mode/dual-mode), the response characteristics (symmetric/asymmetric), and the structure of the filter (modular/non-modular). Last, examples of integrated modules for use in transceiver systems are presented. This part of the research involves the development of duplexers, radiating elements, as well as their integration. The duplexers themselves are realized by integrating a set of band-pass filters and matching networks. The characterization of the individual components, and of the integrated system are included. This research has resulted in a thorough understanding of LCP's electrical performance and its multilayer lamination capabilities pertaining to its functioning as a material platform for integrated microwave systems. Novel passive prototypes that can take advantage of such multilayer capabilities have been developed.
33

Millimeter-wave Analog to Digital Converters: Technology Challenges and Architectures

Shahramian, Shahriar 14 November 2011 (has links)
While data converters have been around for nearly nighty years, mm-wave data converters are still in their infancy. Only recently the 40-GHz sampling barrier was broken with the introduction of the next generation high-speed sampling oscilloscopes. Meanwhile, data communication is the main driving force behind mm-wave data converter development. As with any mm-wave circuit, designers must go beyond simply relying on technology advancement to archives acceptable performance. Careful device and passive modeling is critical and systematic design methodology may o er repeatable and scalable mm-wave designs. In this thesis the design methodology and architectural challenges of mm-wave ADCs are explored. Some of the fundamental mm-wave ADC building blocks such as track and hold ampli ers, data distribution networks and ip- ops are implemented in SiGe BiCMOS and CMOS technologies and characterized. Several record breaking circuits are presented along with systematic design methodology. The impact of these circuit blocks on the performance of the next generation ADCs is studied and experimentally veri ed using a 35-GS/s, 4-bit ADC-DAC chain implemented in a SiGe BiCMOS technology.
34

Millimeter-wave Analog to Digital Converters: Technology Challenges and Architectures

Shahramian, Shahriar 14 November 2011 (has links)
While data converters have been around for nearly nighty years, mm-wave data converters are still in their infancy. Only recently the 40-GHz sampling barrier was broken with the introduction of the next generation high-speed sampling oscilloscopes. Meanwhile, data communication is the main driving force behind mm-wave data converter development. As with any mm-wave circuit, designers must go beyond simply relying on technology advancement to archives acceptable performance. Careful device and passive modeling is critical and systematic design methodology may o er repeatable and scalable mm-wave designs. In this thesis the design methodology and architectural challenges of mm-wave ADCs are explored. Some of the fundamental mm-wave ADC building blocks such as track and hold ampli ers, data distribution networks and ip- ops are implemented in SiGe BiCMOS and CMOS technologies and characterized. Several record breaking circuits are presented along with systematic design methodology. The impact of these circuit blocks on the performance of the next generation ADCs is studied and experimentally veri ed using a 35-GS/s, 4-bit ADC-DAC chain implemented in a SiGe BiCMOS technology.
35

Integrated Antennas and Active Beamformers Technology for mm-Wave Phased-Array Systems

Biglarbegian, Behzad 26 March 2012 (has links)
In this thesis, based on the indoor channel measurements and ray-tracing modeling for the indoor mm-wave wireless communications, the challenges of the design of the radio in this band is studied. Considering the recently developed standards such as IEEE 802.15.3c, ECMA and WiGig at 60 GHz, the link budget of the system design for different classes of operation is done and the requirement for the antenna and other RF sections are extracted. Based on radiation characteristics of mm-wave and the fundamental limits of low-cost Silicon technology, it is shown that phased-array is the ultimate solution for the radio and physical layer of the mobile millimeter wave multi-Gb/s wireless networks. Different phased-array configurations are studied and a low-cost single-receiver array architecture with RF phase-shifting is proposed. A systematic approach to the analysis of the overall noise-figure of the proposed architecture is presented and the component technical requirements are derived for the system level specifications. The proposed on-chip antennas and antenna-in-packages for various applications are designed and verified by the measurement results. The design of patch antennas on the low-cost RT/Duroid substrate and the slot antennas on the IPD technologies as well as the compact on-chip slot DRA antenna are explained in the antenna design section. The design of reflective-type phase shifters in CMOS and MEMS technologies is explained. Finally, the design details of two developed 60 GHz integrated phased-arrays in CMOS technology are discussed. Front-end circuit blocks such as LNA, continuous passive reflective-type phase shifters, power combiner and variable gain amplifiers are investigated, designed and developed for a 60 GHz phased-array radio in CMOS technology. In the first design, the two-element CMOS phased-array front-ends based on passive phase shifting architecture is proposed and developed. In the second phased-array, the recently developed on-chip dielectric resonator antenna in our group in lower frequency is scaled and integrated with the front-end.
36

An Optical Design Configuration for Wireless Data Transmission

Motahari Bidgoli, Seyed Mohammad Amin 11 March 2016 (has links)
The concept of 2D barcodes is of great relevance for use in wireless data transmission between handheld electronic devices. In a typical setup, any file on a cell phone for example can be transferred to a second cell phone through a series of images on the LCD which are then captured and decoded through the camera of the second cell phone. In this research, a new approach for data modulation in 2D barcodes is introduced, and its performance is evaluated in comparison to other standard methods of barcode modulation. In the proposed method, Orthogonal Frequency Division Multiplexing (OFDM) modulation is used together with Differential Phase Shift Keying (DPSK) over adjacent frequency domain elements to modulate intensity of individual pixels. It is shown that the bit error rate performance of the proposed system is superior to the current state of the art in various scenarios. A specific aim of this study is to establish a system that is proven tolerant to camera motion, picture blur and light leakage within neighboring pixels of an LCD. Furthermore, intensity modulation requires the input signal used to modulate a light source to be positive, which requires the addition of a dc bias. In the meantime, the high crest factor of OFDM requires a lower modulation index to limit clipping distortion. These two factors result in poor power efficiency in radio over fiber applications in which signal bandwidth is generally much less than the carrier frequency. In this study, it is shown that clipping a bipolar radio frequency signal at zero level, when it has a carrier frequency sufficiently higher than its bandwidth, results in negligible distortion in the pass band and most of the distortion power is concentrated in the baseband. Consequently, with less power provided to the optical carrier, higher power efficiencies and better receiver sensitivity will result. Finally, a more efficient optical integrated system is introduced to implement the proposed intensity modulation method which is optimized for radio over fiber applications.
37

Advanced physical modelling of step graded Gunn Diode for high power TeraHertz sources

Amir, Faisal January 2011 (has links)
The mm-wave frequency range is being increasingly researched to close the gap between 100 to 1000 GHz, the least explored region of the electromagnetic spectrum, often termed as the 'THz Gap'. The ever increasing demand for compact, portable and reliable THz (Terahertz) devices and the huge market potential for THz system have led to an enormous amount of research and development in the area for a number of years. The Gunn Diode is expected to play a significant role in the development of low cost solid state oscillators which will form an essential part of these THz systems.Gunn and mixer diodes will 'power' future THz systems. The THz frequencies generation methodology is based on a two-stage module. The initial frequency source is provided by a high frequency Gunn diode and is the main focus of this work. The output from this diode is then coupled into a multiplier module. The multiplier provides higher frequencies by the generation of harmonics of the input signal by means of a non-linear element, such as Schottky diode Varactor. A realistic Schottky diode model developed in SILVACOTM is presented in this work.This thesis describes the work done to develop predictive models for Gunn Diode devices using SILVACOTM. These physically-based simulations provide the opportunity to increase understanding of the effects of changes to the device's physical structure, theoretical concepts and its general operation. Thorough understanding of device physics was achieved to develop a reliable Gunn diode model. The model development included device physical structure building, material properties specification, physical models definition and using appropriate biasing conditions.The initial goal of the work was to develop a 2D model for a Gunn diode commercially manufactured by e2v Technologies Plc. for use in second harmonic mode 77GHz Intelligent Adaptive Cruise Control (ACC) systems for automobiles. This particular device was chosen as its operation is well understood and a wealth of data is available for validation of the developed physical model. The comparisons of modelled device results with measured results of a manufactured device are discussed in detail. Both the modelled and measured devices yielded similar I-V characteristics and so validated the choice of the physical models selected for the simulations. During the course of this research 2D, 3D rectangular, 3D cylindrical and cylindrical modelled device structures were developed and compared to measured results.The injector doping spike concentration was varied to study its influence on the electric field in the transit region, and was compared with published and measured data.Simulated DC characteristics were also compared with measured results for higher frequency devices. The devices mostly correspond to material previously grown for experimental studies in the development of D-band GaAs Gunn devices. Ambient temperature variations were also included in both simulated and measured data.Transient solutions were used to obtain a time dependent response such as determining the device oscillating frequency under biased condition. These solutions provided modelled device time-domain responses. The time-domain simulations of higher frequency devices which were developed used modelling measured approach are discussed. The studied devices include 77GHz (2nd harmonic), 125 GHz (2nd harmonic) and 100 GHz fundamental devices.During the course of this research, twelve research papers were disseminated. The results obtained have proved that the modelling techniques used, have provided predictive models for novel Transferred Electron Devices (TEDs) operating above 100GHz.
38

Analytical and Experimental Study of Wide Tuning Range Low Phase Noise mm-Wave LC-VCOs

Elabd, Salma 11 August 2016 (has links)
No description available.
39

Analysis and Design of Wide Tuning Range Low Phase Noise mm-wave LC-VCOs

Wu, Qiyang 21 May 2013 (has links)
No description available.
40

Design Techniques for Manufacturable 60GHz CMOS LNAs

Akour, Amneh M. 25 July 2011 (has links)
No description available.

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