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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.
1

The Study of Electromagnetic Shielding Employing Woven Continuous Carbon Fiber Composites for 2.5Gb/s Transceiver Modules

Lee, Chien-hui 03 July 2004 (has links)
A High electromagnetic shielding, light weight, low cost plastic package is developed by using a woven continuous carbon fiber (WCCF) epoxy composite. Three different weaving types of WCCF, plain¡Bbalanced twill and uni-direction structure, are fabricated for understanding the shielding property of the WCCF composites. By weaving the WCCF in a balanced twill structure with excellent conductive network, it shows that the SE can reach to about 80dB under plane-wave source measurement and about 50dB in the near-field source measurement. By comparison of cost, weight, and shielding performance for optical transceiver modules fabricated by the housings of woven continuous carbon fiber, nanoscale hollow carbon nanocapulses (HCNCs) epoxy composites and nylon and liquid crystal polymer (LCP) with carbon fiber filler composite, the WCCF composites shows lower cost, light weight, and higher electromagnetic shielding than the other types of composites.
2

Communications solution for refugee settlement : Investigation of nRF24L01+ modules for use in a communications network

Engquist, Martin, Bethdavid, Simon January 2018 (has links)
The main purpose of this thesis is to test a communications solution for the second to largest refugee settlement in the world, Bidi Bidi. A solution where it is possible to inform the refugees with necessary information, for example that the water at a specific location is currently contaminated or that food is provided at another location. The idea is to use nRF24L01+ modules which operate in the 2.4 GHz frequency band and send information through various ways. This includes turning LEDs' on and off, sending text Strings and streaming audio. The results showed that the modules are too unreliable for a refugee settlement. They also showed that it is not possible to send other types' of data while streaming audio, but there could be workarounds. It is clear that more knowledge and further investigations are needed.
3

Position estimation for indoor navigation

Ndami, Heri, Hassanzadah, Shahidullah January 2024 (has links)
This project investigates developing and implementing innovative indoornavigation systems by leveraging repurposed Wi-Fi infrastructure anddedicated RFM69HCW transceivers. Aimed at enhancing indoor positioningaccuracy, the study explores the viability of using Received Signal StrengthIndicator (RSSI) and dedicated device localization techniques to overcomethe limitations of existing Global Positioning System (GPS) technology inindoor environments. Through the design and testing of a printed circuit board(PCB) prototype that connects Raspberry Pi Pico (RPP) to RFM69HCWmodules and the development of custom drivers for the RP2040 processor,this research addresses the challenges of indoor navigation, such as signalvariability and environmental interference. The project also emphasizes theimportance of sustainable technology development by repurposing electronicwaste for innovative applications. Findings from the study reveal the potentialof these methodologies to improve indoor positioning accuracy despitechallenges related to hardware compatibility and the dynamic nature of indoorspaces. This research contributes to indoor navigation by demonstrating thefeasibility of using repurposed and dedicated hardware solutions, offeringinsights into future directions for enhancing indoor navigation systems, andhighlighting the role of sustainability in technological innovation.

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