This thesis discusses the investigation and development of design methodologies for the creation of multifunctional band-pass filters capable of tuning to different frequency bands as well as varying their fractional bandwidth. This research also studies polynomial synthesis procedures as a tool for the derivation of reconfigurable planar filters with advanced asymmetrical responses. The work presented here relates to the evolving multifunction philosophy of RF systems. This analysis presents a comprehensive study of microwave resonators, which generate reliable and scalable filter topologies with tunable properties. The study includes the analysis of single, dual and triple-mode filters together with an investigation of the coupling behavior of synchronously and asynchronously tuned resonators. This study identified the main properties responsible for frequency and bandwidth control in a filter, and consequently systematically created innovative design techniques. The research also deals with the development of synthesis procedures for filters with advanced asymmetrical responses. The main goal of this effort is the creation of planar reconfigurable filters with arbitrary assigned transmission zeros. These advanced realizations requite meeting complex design specifications of advanced systems in both commercial and military applications. This work involves an in-depth investigation of polynomial synthesis methods for filters with crossed-coupled resonators and fully canonical form realizations using topologies with source and load coupling.

We report that the tandem OLEDs made of two electroluminescent (EL) units connected by the interconnecting layer. If It is compared wih the traditional OLEDs. The tandem OLEDs have higher efficiency and well lifetime. We not only used the single emitting layer WOLEDs as EL unit but also studied the effect of the interconnecting layer for whole device. First, we designed the interconnecting layer with Alq3¡GLi (1%) (n-doping layer)/MoO3 (p-doping layer), and we optimized the thickness of the interconnecting layer by using green unit cell (Alq3 for EML), ITO/NPB(65 nm)/Alq3(30 nm)/Alq3(30 nm)/Alq3(x nm)¡GLi (1%)/MoO3(y nm)/NPB(65 nm)/Alq3(30 nm)/Alq3(30 nm)/LiF(0.8 nm)/Al(200 nm) x=10¡A20¡A30¡A40¡Fy=1¡A3¡A5¡A7¡A10 We found that the best thickness of Alq3¡GLi (1%) and MoO3 are 20 nm and 5 nm. In our study, we concluded that there are the best thickness to each interconnecting layer, and it keeps the charge balance between two units. Finally, we used our single emitting layer WOLEDs as unit cell, which used 1,3,5-Tri(1-pyrenyl)benzene (TPB3) as the host, and 4-(dicyanomethylene)-2-tert-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) as the guest, unit cell was ITO(130 nm)/NPB(65 nm)/ TPB3(30 nm)¡GDCJTB(0.05%)/ Alq3(30 nm)/LiF(8 nm)/Al(200 nm) Whole device was ITO(130 nm)/NPB(65 nm)/ TPB3(30 nm)¡GDCJTB(0.05%)/ Alq3(30 nm)/Alq3(20 nm)¡GLi(1%)/MoO3(5 nm)/NPB(65 nm)/TPB3(30 nm)¡GDCJTB(0.05%)/Alq3(30 nm)/ LiF(0.8 nm)/Al(200 nm) We got almost three times luminance from the tandem one at the same current density (670 cd/m2 for 2360 cd/m2 at 20 mA/cm2) and efficiency as high as 9.7 cd/A ( at 24 mA/cm2). It¡¦s a excellent contribution for device lifetime. But the operation voltage and the power efficiency didn¡¦t reach to our expectancy. In order to improve the disadvantage, we changed the concentration of n-doping layer Alq3¡GLi (z %)¡Az=1%¡A2%¡A3%. It was actually improved the turn-on voltage from 10 V to 7 V. But the luminescent characteristics also degenerated. Although we enhanced the charge mobility of the n-doping layer, it also caused the degeneration of luminescent characteristics because of the unbalance of the charge transference.We got the efficiency 8.1 cd/A ( at 14 V) and almost two times luminance from the tandem one at the same current density (670 cd/m2 for 1760 cd/m2 at 20 mA/cm2), most close to the white area of CIE coordinates was (0.30 , 0.37) at 15 V. Its range of CIE coordinates was (0.35 , 0.46)~(0.28 , 0.33) at 8 V~20 V. We have already developed the tandem WOLEDs using single white emitting layer as EL units that have never be reported. It not only maintained the advantages of the tandem structure, but also had excellent stability of luminescent characteristics at wide range operation voltage. We reached our goal to improve the WOLEDs and make it more suitable for commercial applications, especially for the development of light sources.

<p>Electronic power devices made of silicon carbide promisesuperior performance over today's silicon devices due toinherent material properties. As a result of the material'swide band gap of 3.2eV, high thermal conductivity, itsmechanical and chemical stability and a high critical electricfield, 4H-silicon carbide devices have the potential to be usedat elevated temperatures and in harsh environments. Shortercarrier lifetimes and a reduction in the necessary width of thelow-doped drift zone in silicon carbide devices compared totheir silicon counterparts result in faster switching speedsand lower switching losses and thus in much more efficientpower devices.</p><p>High-voltage 4H-silicon carbide diodes have been fabricatedin a newly developed processing sequence, using standardsilicon process equipment. Epitaxial layers grown by chemicalvapor deposition (CVD) on commercial 4H-silicon carbidesubstrates were used as starting material for both mesa-etchedepitaxial and implanted p+n-n+ planar diodes, Schottky diodesand merged pn-Schottky (MPS) diodes, together with additionaltest structures. The device metallization was optimized to givea low contact resistivity on implanted and epitaxial layers anda sufficiently high Schottky barrier with a singlemetallization scheme. Different high-field termination designshave been tested and breakdown voltages of up to 4 kV onimplanted, field-ring terminated diodes were achieved,corresponding to 80% of the critical electric field. A 5kVepitaxial diode design with a forward voltage drop of 3.5V at acurrent density of 100Acm-2 equipped with an implanted junctiontermination extension (JTE) was also fabricated.</p><p>A new measurement setup was designed and built with thecapability of measuring current-voltage and capacitance-voltagecharacteristics of semiconductor devices at reverse biases upto 10kV. Together with these electrical measurements, theresults of other characterization techniques were used toidentify performance limiting defects in the fabricated siliconcarbide diodes. Increased forward voltage drop of bipolardevices during on-state operation was studied and it was shownthat the stacking faults causing forward degradation arevisible in scanning electron microscopy. With the help ofsynchrotron white-beam X-ray diffraction topographs (SWBXT),electron beam induced current (EBIC) and electroluminescencemeasurements of silicon carbide diodes, the role of screwdislocations as a dominant source of device failure in the formof localized microplasma breakdown was identified. Screwdislocations with and without open core have been found tocause a 20-80% reduction in the critical electric field of4H-silicon carbide diodes, both for low-voltage (150V) andhigh-voltage (~5kV) designs. While micropipes have almost beeneliminated from commercial silicon carbide material,closed-core screw dislocations are still abundant withdensities in the order of 10000cm-2 in state-of-the-art siliconcarbide epitaxial layers.</p>

Thesis (M.S.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains viii, 80 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 47-51).

Thèse de doctorat : Physique de la matière condensée : Strasbourg 1 : 2004. / Titre provenant de l'écran-titre. Bibliogr. p. 147-153.

Thesis (Master of Business Administration)--Naval Postgraduate School, December 2009. / Thesis Advisors: Dew, Nicholas ; Mutty, John. "December 2009." Description based on title screen as viewed on January 26, 2010. Author(s) subject terms: LED lighting, solid state lighting, business case analysis. Includes bibliographical references (p. 81-83). Also available in print.

Thesis (Master of Business Administration)--Naval Postgraduate School, December 2009. / Thesis Advisor(s): Dew, Nicholas. Second Reader: Hudgens, Bryan. "December 2009." Description based on title screen as viewed on January 28, 2010. Author(s) subject terms: Lighting, LEDs, shipboard lighting. Includes bibliographical references (p. 31-32). Also available in print.

Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Bibliography: leaves 71-72.

Thesis (Ph. D.)--Ohio State University, 2004. / Title from first page of PDF file. Document formatted into pages; contains xv, 150 p.; also includes graphics (some col.). Includes abstract and vita. Advisor: Jonathan P. Pelz, Dept. of Physics. Includes bibliographical references (p. 144-150).

Thesis (Ph. D.)--University of Texas at Austin, 2003. / Vita. Includes bibliographical references. Available also from UMI Company.