A crosstalk analysis model for optical network-on-chip based on WDM is proposed. The crosstalk noise and signal-to-noise-ratio of multiple wavelengths networks are analyzed. And a case study is presented to evaluate the proposed crosstalk model.
This paper presents a generic and complete process to characterize and model the newly developed silicon carbide (SiC) MOSFET. The static characteristics, including MOSFET I-V curves, body diode, nonlinear junction capacitances, as well as package stray inductances, have been fully characterized on a prototype 1.2 kV, 20 A SiC MOSFET under varying temperature from 25degC to 200degC. Characteristics particular to the SiC MOSFET and its advantages over the silicon counterparts are analyzed and explained. The switching performance of the device, on the other hand, has also been tested under room temperature using a specially designed double-pulse tester with minimized circuit parasitics. The characterization results are then used to build a SiC MOSFET model using the MOSFET modeling tool in Synopsys Saber. Finally, discussions are presented on how to improve the model accuracy in its switching behavior by obtaining static characteristics from switching waveforms.
Abstract Invoking the occurrence of pyroptosis is an emerging strategy for the treatment of cancer. However, the practical applications of pyroptosis for cancer therapy are currently hindered due to the lack of tumor‐specific and efficient pyroptotic agents in vivo. Herein, a virus‐spike tumor‐activatable pyroptotic agent (VTPA) for cancer‐specific therapy is reported. The VTPA is composed of an organosilica coated iron oxide nanoparticle core and spiky manganese dioxide protrusions, which can readily accumulate in tumor after systemic administration, facilitate the tumor intracellular lysosomal rupture, and be degraded by tumor over‐expressed intracellular glutathione (GSH) to release Mn ions and iron oxide nanoparticles (IONPs) for the synergetic activation of nucleotide binding oligomerization domain‐like receptors protein 3 (NLRP3) inflammasomes. Consequently, the activation of NLRP3 inflammasomes and the release of lactate dehydrogenase of tumor cells are observed after the treatment of VTPA, resulting in a specific pyroptotic cell death. To our best knowledge, the structure‐dependent and tumor intracellular GSH activatable pyroptotic agents represent the first demonstration of cancer‐specific pyroptosis in vivo, providing a novel paradigm for the development of next‐generation cancer‐specific pyroptotic nanomedicine.
A novel absorptive bandstop microstrip filter utilizing two couplers is presented in this letter. The proposed absorptive bandstop filer (ABSF) with four ports is achieved by combing two quadrature couplers with two conventional microstrip bandstop filters. Unwanted energy within the stopband will be absorbed by absorptive port instead of reflecting to incident port so that the property of absorption could be realized. The theory is analyzed and a microstrip bandstop filter with a center frequency f0 of 5GHz is demonstrated and simulated, the maximal stopband rejection is 38 dB with an input return loss of 31 dB, which implies that almost of the input power is dissipated by the proposed ABSF.
This paper presents a design methodology for an optimal DC-link RC snubber that can effectively suppress the parasitic ringing in high-speed, hard-switched converters with modern SiC MOSFETs. Unlike the traditional RC snubber across the switch, a snubber across the DC-link dampens only the high-frequency ringing and doesn't increase the switching loss. By analyzing a small-signal impedance network relating the time-domain ringing to the frequency-domain Bode plot, this work derives the R-C combination that achieves the best damping effect. Closed-form expressions are developed so that this method can be easily implemented in actual designs.
We propose and experimentally demonstrate a segmented waveguide taper (SWT) mode adapter for a polarization mode converter to reduce excess loss induced by a 100-μm-wide waveguide gap housing a 92-μm-thick quartz half waveplate. The SWT mode adapter is a combination of periodically segmented waveguide taper and traditional taper formed in a silica-based waveguide. It is proved that this SWT mode adapter requires no vertical tapering process but can enlarge the mode size in both vertical and horizontal directions. Our newly designed SWT mode adapter based on the 0.75%-Δ silica waveguide is able to reduce the excess loss significantly from 5 dB to less than 1.5 dB.
This work presents a novel hybrid packaging structure for high-temperature SiC power modules that combines the benefits of both the wirebond structure and the planar structure. With the hybrid structure, the power modules can achieve the same footprint and similar parasitics, but much easier fabrication process and more reliable top-side interconnections, compared with regular planar structures. The new structure and its fabrication process are presented and a prototype module is built based on SiC JFET. Detailed comparisons are also conducted between the hybrid, planar, and wirebond structures. The results reveal the better performances of the hybrid structure in smaller parasitics than the wirebond structure, and easier fabrication than the planar structure. Finally, a multiple chips hybrid structure power module is built and tested in high temperature.
This paper presents a methodology for modeling the high-voltage silicon carbide (SiC) MOSFET/Junction-Barrier Schottky (JBS) diode power modules. The electrical model of an actual high-voltage SiC MOSFET/JBS module has been obtained using computer-aided electromagnetic analysis and verified through measurements. A circuit simulation model of a 2 kV, 5 A 4-H SiC MOSFET has also been built based on Hefner MOSFET model and the published experimental data. The device and package models are then combined together in the circuit simulation of a double-pulse test. The simulation results obtained provide good insight into the fast switching behavior and parametric dependencies of the paralleled SiC dice, which will aid in the module physical layout and gate driver design, as well as switching and conduction loss analysis.
In this paper, a high-temperature, high-frequency, wire-bond-based multichip phase-leg module was designed, fabricated, and fully tested. Using paralleled Silicon Carbide (SiC) MOSFETs, the module was rated at 1200 V and 60 A, and was designed for a 25-kW three-phase inverter operating at a switching frequency of 70 kHz, and in a harsh environment up to 200 °C, for aircraft applications. To this end, the temperature-dependent characteristics of the SiC MOSFET were first evaluated. The results demonstrated the superiority of the SiC MOSFET in both static and switching performances compared to Si devices, but meanwhile did reveal the design tradeoff in terms of the device's gate oxide stability. Various high-temperature packaging materials were then extensively surveyed and carefully selected for the module to sustain the harsh environment. The electrical layout of the module was also optimized using a modeling and simulation approach, in order to minimize the device parasitic ringing during high-speed switching. Finally, the static and switching performances of the fabricated module were tested, and the 200 °C continuous operation of the SiC MOSFETs was verified.
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