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In standard power cycling tests, forward conduction generates heat in the die and therefore the ther-momechanical stress in the package. In application, however, a significant part of the power losses are switching losses, so that the load current is lower than in standard power cycling test, for an equal temperature swing. A new concept for power cycling tests is presented, which allows the generation...
We demonstrate, for the first time with a DFB-MZM at 1550 nm, 100-GBd NRZ and PAM4 transmission over up to 1.2 km due to close-to-zero chirp. At 100-GBd PAM4, the DFB-MZM consumed only 0.85 pJ/bit.
We generate record-high line rates of 400 Gbit/s (100 GBd 16QAM) using a silicon-based IQ modulator. With a BER=1.9×10"2 we transmit a net data rate of 333 Gbit/s, the highest value for a semiconductor-based modulator.
The evaluation of power cycling results needs correct measurement of the course of thermal resistance. Hence an accurate online measurement of the junction temperature is necessary. Different measurement and power cycling methods were evaluated. The method of measuring the voltage drop of the SiC MOSFET body diode pn-junction at low measurement current with sufficient negative gate-voltage was found...
We show 64 GBd 4ASK signaling with a silicon-organic hybrid Mach-Zehnder modulator, allowing data rates of up to 128 Gbit/s. The device is operated at room temperature and at 80 °C.
The prevalence of multi-core processors means application developers can no longer ignore concurrency and its attendant problems of data races, deadlock, safety, and liveness. Imperative languages such as Java and C, based on shared, mutable state, have added locks, semaphores and condition variables to address these problems; unfortunately, these locking approaches are notoriously error-prone.
Traditional approaches to addressing issues of concurrency rely on mechanisms added to standard imperative languages such as Java, such as “synchronized” methods and blocks, combined with a “wait/notify” mechanism used to block and awaken processes when a shared resource is not in an acceptable state. The problem with this approach, however, is that mutable state is potentially accessible via many...
Until recently, those who taught mathematical modeling (or “formal methods”) faced daunting challenges. First, most modeling tools used seemingly esoteric notations that were hurdles for many students. Even if the notation could be tamed, the tools themselves were rarely more than syntax checkers, possibly with support for simple expression evaluation. Venturing beyond this requires understanding...
Identity Federations are increasingly being used to establish convenient and secure attribute-based authentication and authorization systems. Whilst this process began mainly in the academic sector, it is assumed that over the next few years more and more commercial Service Providers will join Identity Federations in order to offer their services and products to federated customers. However, the introduction...
Student retention is a challenge faced by all engineering programs. Our first year software engineering students have schedules filled with computer science, mathematics, science and humanities. The lack of any exposure to engineering meant some students, expressing a dislike for software engineering, left the program before they had any exposure to the discipline. To address this issue, we created...
The IGBT can run into different short-circuit types (SC I, SC II, SC III). Especially in SC II and III, an interaction between the gate drive unit and the IGBT takes place. A self-turn-off mechanism after short-circuit turn on can occur. Parasitic elements in the connection between the IGBT and the gate unit as well as asymmetrical wiring of devices connected in parallel are of effect to the short-circuit...
We present the first real-time transmitter generating a multicarrier offset-QAM signal at 224 Gb/s after polarization multiplexing. Low penalties are achieved in a back-to-back experiment using a novel FPGA platform including two high-speed DACs running at 32 GS/s.
This paper shows how a buried aluminum eutectic drop at the cathode-side of a high-voltage power diode can affect the device behavior. The aluminum drop driven by thermo-migration, moves from the contact metallization some micrometers into the chip and forms a buried eutectic. Thermomigration [1] becomes stronger as the temperature gradient increases. High temperature gradients can be achieved at...
This work compares the performance of “Liquid Pin” coolers and other advanced cooling techniques like “ShowerPower”, pin fin and microchannel. Water glycol mixture (40% v/v glycol) is used as a cooling agent at temperatures of 5 °C, 20 °C, 40 °C and 60 °C. Various characteristics of the coolers like pressure drop, thermal resistance and impedance are examined.
OFDM has emerged as a promising modulation technique in long-haul and access optical networks. The computational complexity of the format can be met with powerful digital signal processors, and especially by exploiting all-optical signal processing.
Nowadays, eProcurement, i.e. purchasing goods and services online in a business-to-business or business-to-government transaction, is being seen as a growing opportunity for companies to sell their products. However, today, eProcurement is being carried out by static and inconvenient solutions. Current approaches do not support dynamic federation establishment, automatic payment or a reliable on-the-fly...
In this publication, test results of power cycling tests are presented with 600V IGBT power modules for hybrid electrical vehicle (HEV) applications at high junction temperatures. First, the power cycling capability of standard packaging technology in wide ΔTj range is investigated. Afterwards the reliability improvement of new packaging technologies is shown.
The paper discusses the state of the art of implementations and applications of sensorless control in industrial frequency inverters. Implementations for speed and position controlled drives are shown using either EMF based flux estimators or an Extended Kalman Filter (EKF) with signal injection to evaluate the saliencies of the machines for speed and position detection. Applications are presented...
Due to the feedback of free carriers to the electric field, branches with negative differential resistance (NDR) occur in high power devices. NDR usually leads to current filaments. These current filaments might be non-destructive if they move. Most critical effects are found if impact ionization occurs at the n--n+-junction with a positive electrical feedback to avalanche or dynamic avalanche at...
The management of services offered within identity federations comprises not only the traditional service elements but also those management requirements derived from the federation's specification. However, since a discrepancy between the management needs related to payment and the capabilities offered by the federation's protocols can be observed, this paper aims to provide a solution to bridge...
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