Inst. Hochfrequenz- und Halbleiter-Systemtechnologien

167 Items

Recent Submissions
Materialaspekte der Hydridgasphasenepitaxie von Aluminiumgalliumnitrid

Fleischmann, Simon (2019)

In dieser Arbeit wurden Aspekte zur Verbesserung der Materialqualität von AlGaN-Schichten untersucht, die mittels HVPE abgeschieden wurden. Diese umfassten einerseits die Strukturierung von Saphirsubstraten und die Prozessschritte Pufferschicht und Kompositionsvariationen sowie andererseits die Wahl des Reaktormaterials zu Vermeidung von parasitären Reaktionen und Fremdatomeinbau. Zunächst wur...

Investigation of perovskite-CIGSe tandem solar cells

Wang, Yajie (2019)

Multi-junction photovoltaic devices have received much attention for a long time due to their potential performance beyond the Shockley-Queisser (S-Q) limit compared with the current (commercially available) single junction solar cells. Thin film solar cells based on polycrystalline Cu(In,Ga)(S,Se)2 (CIGSe) absorbers and hybrid organic-inorganic perovskite solar cells have reached power convers...

Optical feedback effects within 1.55 μm InP-based DFB laser integrated Mach-Zehnder modulators for up to 100 GBd data transmission

Lange, Sophie Gloria (2019)

Indium phosphide-based 1550 nm wavelength optical transmitters are developed, suitable for next generation transceiver modules for intra- and inter-data center connections from a few kilometers to tens of kilometers range. The challenges of designing high-speed, low power and low-cost transceivers for future data centers are met by integrating a high bandwidth and low switching voltage travelli...

GaAs-based components for photonic integrated circuits

Arar, Bassem (2019)

Semiconductor lasers based on GaAs/AlGaAs double heterostructures have recently received increasing interest for atomic spectroscopy applications. For example GaAs/AlGaAs double heterostructure laser radiation at the wavelengths of 780 nm and 1064 nm is used for rubidium spectroscopy, and for molecular iodine spectroscopy (at 532 nm using frequency-doubling techniques), respectively. Optical sy...

A 216–256 GHz fully differential frequency multiplier-by-8 chain with 0 dBm output power

Eissa, Mohamed Hussein ; Malignaggi, Andrea ; Ko, Minsu ; Schmalz, Klaus ; Borngräber, Johannes ; Ulusoy, Ahmet Cagri ; Kissinger, Dietmar (2018-03-05)

This work presents a fully differential wideband and low power 240 GHz multiplier-by-8 chain, manufactured in IHP's 130 nm SiGe:C BiCMOS technology with fT/fmax = 300/500 GHz. A single ended 30 GHz input signal is multiplied by 8 using Gilbert cell-based quadrupler and doubler, and then amplified with a wideband differential 3-stage cascode amplifier. To achieve wide bandwidth and optimize for ...

New TCO for use as transparent front contact in chalcopyrite thin film solar cells

Erfurt, Darja (2019)

In this thesis the applicability of high-mobility indium oxide based transparent conductive oxides (TCOs) as front contact in Cu(In,Ga)(S,Se)2 (CIGS) solar cells and modules was investigated. The unique trade-off between optical and electrical properties promises improved short circuit current densities compared to conventional CIGS device configurations, in particular in CIGS modules. By dopin...

Octave bandwidth S- and C-band GaN-HEMT power amplifiers for future 5G communication

Rautschke, Felix ; May, Stefan ; Drews, Sebastian ; Maaßen, Daniel ; Böck, Georg (2018-06-21)

In this contribution, a design methodology for octave-bandwidth power amplifiers (PA) for 5G communication systems using surface mount dual-flat-no-lead packaged gallium-nitride high-electron-mobility transistor devices is presented. Systematic source- and load-pull simulations have been used to find the optimum impedances across 75% fractional bandwidth for S- (1.9–4.2 GHz) and C-band (3.8–8.4...

Development and characterisation of a diode laser based tunable high-power MOPA system

Tawfieq, Mahmoud (2019)

The aim of this work is to develop and characterize widely tunable high power diode lasers emitting at 976 nm, to serve in non-linear frequency conversion applications. In particular, to serve as pump sources in infrared upconversion detection systems. This is realized by a master oscillator power amplifier (MOPA) configuration, where the MO provides the wavelength stabilization and tuning, whi...

Crystallisation Phenomena of In2O3:H Films

Muydinov, Ruslan ; Steigert, Alexander ; Wollgarten, Markus ; Michałowski, Paweł Piotr ; Bloeck, Ulrike ; Pflug, Andreas ; Erfurt, Darja ; Klenk, Reiner ; Körner, Stefan ; Lauermann, Iver ; Szyszka, Bernd (2019-01-15)

The crystallisation of sputter-deposited, amorphous In2O3:H films was investigated. The influence of deposition and crystallisation parameters onto crystallinity and electron hall mobility was explored. Significant precipitation of metallic indium was discovered in the crystallised films by electron energy loss spectroscopy. Melting of metallic indium at ~160 °C was suggested to promote primary...

Realisierung eines piezo-resistiven Niederdruck-Sensors in der SOI-Technologie zum Einsatz in Hochtemperatur- und aggressiver Umgebung

Mukhopadhyay, Biswajit (2019)

Es besteht seitens der Automobil- und Kunststoffindustrie seit geraumer Zeit ein großer Bedarf an hochtemperaturtauglichen Drucksensorsystemen, welche z.B. im Motoreinlass und –auslass sowie RIM (Reaction Injection Moulding) eingesetzt werden können. Solche Hochtemperaturdrucksensoren können z.B. helfen, die Schadstoffemission und den Verbrauch von Verbrennungsmotoren zu reduzieren. Im Rahmen ...

Multi-Octave bandwidth, 100 W GaN power amplifier using planar transmission line transformer

Arnous, Mhd Tareq ; Zhang, Zihui ; Rautschke, Felix ; Böck, Georg (2017)

In this paper, design, implementation, and experimental results of efficient, high-power, and multi-octave gallium nitride-high electron mobility transistor power amplifier are presented. To overcome the low optima source/load impedances of a large transistor, various topologies of a broadside-coupled impedance transformer are simulated, implemented, and measured. The used transformer has a fla...

Electromagnetic and small-signal modeling of an encapsulated RF-MEMS switch for D-band applications

Tolunay Wipf, Selin ; Göritz, Alexander ; Wietstruck, Matthias ; Wipf, Christian ; Tillack, Bernd ; Mai, Andreas ; Kaynak, Mehmet (2017)

In this work, an electromagnetic (EM) model and a small-signal (lumped-element) model of a wafer-level encapsulated (WLE) radio frequency microelectromechanical systems (RF-MEMS) switch is presented. The EM model of the WLE RF-MEMS switch is developed to estimate its RF performance. After the fabrication of the switch, the EM model is used to get accurate S-parameter simulation results. Alterna...

Design and layout strategies for integrated frequency synthesizers with high spectral purity

Herzel, Frank ; Kissinger, Dietmar (2017)

Design guidelines for fractional-N phase-locked loops with a high spectral purity of the output signal are presented. Various causes for phase noise and spurious tones (spurs) in integer-N and fractional-N phase-locked loops (PLLs) are briefly described. These mechanisms include device noise, quantization noise folding, and noise coupling from charge pump (CP) and reference input buffer to the ...

Optimization of broad-area GaAs diode lasers for high powers and high efficiencies in the temperature range 200-220 K

Frevert, Carlo (2018)

GaAs-based high-power broad area (BA) diode lasers are the most efficient light source in converting electrical into optical energy. Their high power densities, small footprint and high reliability make them essential tools for industrial and scientific applications. In addition, their adjustable wavelength (by choice of semiconductor material) enables their use as optical pumps for a wide rang...

GaN-HEMT power amplifiers and smart transmitters for Ku-band satellite communication

Maaßen, Daniel (2018)

Within this contribution the design, implementation, and experimental results of a satellite communication (SatCom) power amplifier (PA), block upconverter (BUC) as well as an evaluation within the satellite link are described. Three Ku-band GaN-HEMT PAs are presented. A two stage design approach with two 250 nm bare-die devices has been chosen to achieve a considerably high saturated gain of 1...

Concept development and implementation of online monitoring methods in the transfer molding process for electronic packages

Kaya, Burcu (2018)

The transfer molding process is one of the major processes for the encapsulation of electronic packages. To provide a structural support and to protect the electronic components from the environment, epoxy molding compounds (EMCs) are mainly used as encapsulation material. The quality of the molded packages depends strongly on the process parameters of the transfer molding process and also the ...

Tailor-made light management textures for liquid phase crystallized silicon solar cells

Eisenhauer, David (2018)

The aim of this thesis is the identification and implementation of tailored light management textures for liquid phase crystallized silicon thin-film solar cells on glass. To do this, textures that combine excellent anti-reflective properties in the wavelength range of interest and a consistent silicon material quality compared to reference cells need to be established. Two approaches for light...

Interdigitated back contact silicon heterojunction solar cells

Stang, Johann-Christoph (2018)

This work follows two routes: the first one explores the efficiency potential of IBC SHJ solar cells built with a rather complex process, the second one shows ways to make this efficiency potential actually industrially accessible by developing an appropriate, simplified manufacturing process. In chapter 4, both manufacturing processes are discussed. In the first part, the established photolit...

Wideband GaN microwave power amplifiers with class-G supply modulation

Wolff, Nikolai (2018)

The continuous and rapidly growing demand for mobile communication access led worldwide to a major increase in the number of base stations to provide the sufficient coverage and quality of service. As a consequence, mobile communication networks have become a significant contributor to the worldwide energy consumption. The necessity to save operational cost and the increased energy awareness fu...

Modeling and characterization of PCB coils for inductive wireless charging

Curran, Brian ; Maaß, Uwe ; Fotheringham, Gerhard ; Stevens, Nobby ; Ndip, Ivan ; Lang, Klaus-Dieter (2015)

Wireless charging is emerging as a viable technology in many industries, including consumer, medical, and sensor electronics. An investigation of design principles is conducted for a wireless charging platform that is designed to charge devices of different sizes and technologies, using only through vias. It is shown that at a 5 mm separation distance, a coupling coefficient can be achieved whi...