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Simulation of microwave circuits and laser structures including PML by means of FIT
2004, Hebermehl, G., Schefter, J., Schlundt, R., Tischler, Th., Zscheile, H., Heinrich, W.
Field-oriented methods which describe the physical properties of microwave circuits and optical structures are an indispensable tool to avoid costly and time-consuming redesign cycles. Commonly the electromagnetic characteristics of the structures are described by the scattering matrix which is extracted from the orthogonal decomposition of the electric field. The electric field is the solution of an eigenvalue and a boundary value problem for Maxwell’s equations in the frequency domain. We discretize the equations with staggered orthogonal grids using the Finite Integration Technique (FIT). Maxwellian grid equations are formulated for staggered nonequidistant rectangular grids and for tetrahedral nets with corresponding dual Voronoi cells. The interesting modes of smallest attenuation are found solving a sequence of eigenvalue problems of modified matrices. To reduce the execution time for high-dimensional problems a coarse and a fine grid is used. The calculations are carried out, using two levels of parallelization. The discretized boundary value problem, a large-scale system of linear algebraic equations with different right-hand sides, is solved by a block Krylov subspace method with various preconditioning techniques. Special attention is paid to the Perfectly Matched Layer boundary condition (PML) which causes non physical modes and a significantly increased number of iterations in the iterative methods.
Epitaxie, Herstellung, und Charakterisierung von III-N basierenden Deep-UV LEDs mit Schwerpunkt auf dem UV-B bis UV-C, Teilvorhaben : Projekt-Abschlussbericht ; im Verbundvorhaben: Deep-UV LEDs auf der Basis von (AlGaln)N/GaN Quantenfilmen für den UV-A, UV-B und UV-C Wellenlängenbereich
2011, Weyers, M., Knauer, A., Einfeldt, Sven, Rodriguez, Hernan, Kneissl, M., Knüller, V., Tessaro, T., Petzke, T
[no abstract available]
Strategieförderung: Strategische Kooperation zur gemeinsamen Verwertung in Mikrowellentechnik, Optoelektronik und Plasmatechnologie, Kurzbezeichnung: VALORES: Valorisation of Research - Strategic Cooperation of Institutes
2010, Niehardt, Frank, Grzeganek, Merit, Häckel, Marko, Haselton, Kirk, Kerl, Ralf, Sauer, Franziska
[no abstract available]
Mehr-Sektions DBR-Laser mit einstellbarem sättigbarem Absorber zur Erzeugung kurzer Impulse mit hoher Leistung und geringem Chirp für die Frei-Raum Kommunikation : Abschlussbericht ; Berichtszeitraum: 15.4.2000 - 30.6.2004
2004, Hasler, Karl Heinz, Wenzel, Hans, Klehr, Andreas, Knauer, Arne, Fricke, Jörg, Janke, Bernd, Erbert, Götz, Schwertfeger, Sven
[no abstract available]
Effect of electron blocking layer doping and composition on the performance of 310 nm light emitting diodes
2017, Kolbe, Tim, Knauer, Arne, Rass, Jens, Cho, Hyun Kyong, Hagedorn, Sylvia, Einfeldt, Sven, Kneissl, Michael, Weyers, Markus
The effects of composition and p-doping profile of the AlGaN:Mg electron blocking layer (EBL) in 310 nm ultraviolet B (UV-B) light emitting diodes (LEDs) have been investigated. The carrier injection and internal quantum efficiency of the LEDs were simulated and compared to electroluminescence measurements. The light output power depends strongly on the temporal biscyclopentadienylmagnesium (Cp 2 Mg) carrier gas flow profile during growth as well as on the aluminum profile of the AlGaN:Mg EBL. The highest emission power has been found for an EBL with the highest Cp 2 Mg carrier gas flow and a gradually decreasing aluminum content in direction to the p-side of the LED. This effect is attributed to an improved carrier injection and confinement that prevents electron leakage into the p-doped region of the LED with a simultaneously enhanced carrier injection into the active region.
Hochbitratige Schaltungen mit InP-HBTs : Schlussbericht
2005, Heinrich, W., Brunner, F., Kurpas, P., Meliani, C., Rudolph, M., Sidorov, V., Würfl, J.
[no abstract available]
GaN MMICs für Class-S Leistungsverstärker (GaN-Switchmode) : Schlussbericht
2010, Würfl, Joachim, Wentzel, Andreas, Heinrich, Wolfgang, Meliani, Chafik, Lossy, Richard
[no abstract available]
Kohärente Strahlquelle für die optische Freiraumkommunikation auf der Basis von hybrid integrierten Diodenlasern und Halbleiterlaser-Verstärkern : Abschlussbericht
2012, Tränkle, G., Erbert, G., Wicht, A., Spiessberger, S.
[no abstract available]
Technologie- und Epitaxieentwicklung von AlGaN/GaN HFETs: Materialgüte, innovative Prozesstechnologie und Zuverlässigkeit : Schlussbericht
2007, Würfl, J., Behtash, R., Gesche, R., Janke, B., Klockenhoff, H., Krüger, O., Lossy, R., Chaturvedi, N., Heinrich, W., Knigge, St., Liero, A., Mai, M.
[no abstract available]
Wirtschaft trifft Wissenschaft: Leibniz-Transferverbund Mikroelektronik : Schlussbericht
2011, Kerl, Ralf
[no abstract available]