• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 9
  • 2
  • 1
  • Tagged with
  • 20
  • 20
  • 20
  • 4
  • 4
  • 4
  • 4
  • 4
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 3
  • 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.
11

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.
12

DESIGN AND FABRICATION OF POLYNORBORNENE- AND LIQUID CRYSTAL POLYMER-BASED ELECTRODE ARRAYS FOR BIOMEDICAL APPLICATIONS

Hess, Allison Elizabeth 04 April 2008 (has links)
No description available.
13

Investigation of the Flowfield Surrounding Small Photodriven Flapping Wings

Bani Younes, Ahmad Hani 19 August 2009 (has links)
No description available.
14

Development of system level integration of compact RF components on multilayer liquid crystal polymer (LCP)

Chung, David 25 August 2011 (has links)
A system packaging level approach on liquid crystal polymer (LCP) was proposed for low cost, lightweight, and compact wireless communication systems. Via technology was explored for V-band W-band transitions and an active cooling system that are essential for compact multilayer integration. RF MEMS switches were fabricated and integrated at the component level to enable multi-functional devices with optimal performance. A pattern reconfigurable antenna for MIMO applications and 3D phase shifters for phased array antennas that use RF MEMS switches were presented. In addition, a lightweight expandable array was designed and measured with up to 256 elements on multilayer LCP integrated at the system level. Furthermore, a 60 GHz multilayer transceiver front end device with simultaneous transmit and receive was designed and measured for low cost 60 GHz applications. The wide variety of multilayer LCP applications integrated at the system level shows a promising future for the next generation low cost lightweight wireless communication systems.
15

Design and development of organically packaged components and modules for microwave and Mm-wave applications

Khan, Wasif Tanveer 12 January 2015 (has links)
Because of the tremendous amount of media streaming, video calling and high definition TV and gaming, the biggest challenge for the wireless industry is the increasing demand of high data rates. Utilization of mm-wave frequencies is an attractive option to meet this high demand. Recent advances in low cost semiconductor technologies allow realization of low-cost on-chip RF front-ends in the high millimeter wave (mm-wave) frequencies, making it possible to realize compact systems for these application areas. Although integrated circuits (ICs) are one of the main building blocks of a mm-wave system, in order to realize a fully functional wireless system, cost-effective antenna design and packaging are two important pre-conditions. Researchers have investigated and reported low-cost electronics packaging up to 100 GHz to a great extent on ceramic substrates, but mm-wave packaging above 100 GHz is relatively less explored, particularly on organic substrates. This Ph.D. dissertation demonstrates the design and development of microwave and mm-wave on-chip and on-package antennas and organically packaged components and modules ranging from 20 GHz to 170 GHz. The focus of this research was to design and develop mm-wave components and modules on LCP, to investigate the viability of this organic substrate and development of fabrication techniques in the K- (18-26.5 GHz), V- (50 to 70 GHz), W- (75 to 110 GHz), and D- (110 to 170 GHz) bands. Additionally, a demonstration of a micro-machined on-chip antenna has also been presented. This dissertation is divided in three parts: (1) characterization of liquid crystal polymer from 110 to 170 GHz. (2) development of highly radiation efficient on-chip and AiP antennas, and (3) development of mm-wave modules with the integration of antennas.
16

FLEXOELECTRIC LIQUID CRYSTALS AND THEIR APPLICATIONS

Jiang, Yingfei 26 July 2020 (has links)
No description available.
17

Examining the Effectiveness of Different Mixing Elements in the Twin Screw Compounding of Liquid Crystal Polymer and Polypropylene

Agrawal, Akash 02 February 2018 (has links)
No description available.
18

Exploration of liquid crystal polymer packaging techniques for rf wireless systems

Patterson, Chad E. 03 July 2012 (has links)
In the past decade, there has been an increased interest in low-cost, low-power, high data rate wireless systems for both commercial and defense applications. Some of these include air defense systems, remote sensing radars, and communication systems that are used for unmanned aerial vehicles, ground vehicles, and even the individual consumer. All of these applications require state-of-the-art technologies to push the limits on several design factors such as functionality, weight, size, conformity, and performance while remaining cost effective. There are several potential solutions to accomplish these objectives and a highly pursued path is through the utilization of advanced integrated system platforms with high frequency, versatile, multilayered materials. This work intends to explore advanced 3-D integration for state-of the art components in wireless systems using LCP multilayer organic platforms. Several packaging techniques are discussed that utilize the inherent benefits of this material. Wire bond, via interconnect, and flip-chip packages are implemented at RF and millimeter-wave (mm-wave) frequencies to explore the benefits of each in terms of convenience, reliability, cost, and performance. These techniques are then utilized for the demonstration of bulk acoustic waveguide (BAW) filter applications and for the realization of highly integrated phased-array antenna systems.
19

Characterization and Design of Liquid Crystal Polymer (LCP) Based Multilayer RF Components and Packages

Thompson, Dane C. 11 April 2006 (has links)
This thesis discusses the investigation and utilization of a new promising thin-film material, liquid crystal polymer (LCP), for microwave and millimeter-wave (mm-wave [>30 GHz]) components and packages. The contribution of this research is in the determination of LCP's electrical and mechanical properties as they pertain to use in radio frequency (RF) systems up to mm-wave frequencies, and in evaluating LCP as a low-cost substrate and packaging material alternative to the hermetic materials traditionally desired for microwave circuits at frequencies above a few gigahertz (GHz). A study of LCP's mm-wave material properties was performed. Resonant circuit structures were designed to find the dielectric constant and loss tangent from 2-110 GHz under both ambient and elevated temperature conditions. Several unique processes were developed for the realization of novel multilayer LCP-based RF circuits. These processes include thermocompression bonding with tight temperature control (within a few degrees Celsius), precise multilayer alignment and patterning, and LCP laser processing with three different types of lasers. A proof-of-concept design that resulted from this research was a dual-frequency dual-polarization antenna array operating at 14 and 35 GHz. Device characterization such as mechanical flexibility testing of antennas and seal testing of packages were also performed. A low-loss interconnect was developed for laser-machined system-level thin-film LCP packages. These packages were designed for and measured with both RF micro-electromechanical (MEM) switches and monolithic microwave integrated circuits (MMICs). These research findings have shown LCP to be a material with uniquely attractive properties/capabilities for vertically integrated, compact multilayer LCP circuits and modules.
20

WAVEGUIDE LIQUID CRYSTAL DISPLAYS AND OPTICAL DIFFRACTION GRATING BASED ON FLEXOELECTRIC LIQUID CRYSTALS AND POLYMER STABILIZED LIQUID CRYSTALS

Shin, Yunho 24 April 2023 (has links)
No description available.

Page generated in 0.079 seconds