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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 Processing and Evaluation of Long Lived GaA1As Channeled Substrate Planar Lasers

Look, Christopher 09 1900 (has links)
Part B of two parts. Part A found at: http://hdl.handle.net/11375/18724 / <p> The theory of operation and advantages of a channeled substrate planar (CSP) laser is described. The processing of such devices utilizing 5 N m wide proton bombardment defined current stripes is detailed. The optical and electrical characteristics of the resultant devices is presented. The lasers had pulsed, room temperature thresholds averaging 90mA, lased predominantly in a single longitudinal mode and were kink-free to power levels in excess of 6mW. Accelerated aging yielded an "activation energy" for the degradation process of 0.7eV which allowed for a predicted useful lifetime of 5 x 10^4 hours for these lasers. </p> / Thesis / Master of Engineering (MEngr)
2

Antény na flexibilním substrátu / Flexible substrate antennas

Sedlák, Jakub January 2020 (has links)
This diploma thesis deals with a design of antennas based on a flexible substrate. There is also a design of a transmission line between a flexible and rigid substrate with FLEX- RIGID technology. In the first part of thesis, there is the technology, advantages and disadvantages of using this technology in design of antennas mentioned. There are also basic antenna parameters mentioned. In second part, the design of a transmission line and four antennas is presented. Two of these antennas are manufactured and measured. Finally, the measured parameters are compared with the simulated results.
3

Trychtýřová anténa integrovaná do textilu / Textil Integrated Horn Antenna

Jaroš, Ondřej January 2017 (has links)
This diploma thesis describes the corrugated substrate integrated horn antenna designed to surface wave’s excitation in the UWB band groups 3, 4, 5 and 6 (6 – 10 GHz). The antenna is integrated into 3,4 mm thick textile with relative permittivity r = 1,195. The coaxial cable is connected via the SMA connector that is attached to the aluminum bracket. From the microstrip line transition the corrugated substrate integrated waveguide is excited. Two strip lines are placed in front of the aperture for improvement of the impedance matching. The directivity of the antenna is 12 dBi at 8 GHz. At the same frequency, the antenna efficiency is 70%.

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