A SiC BJT-Based Negative Resistance Oscillator for High-Temperature Applications

Abstract

This brief presents a 59.5 MHz negative resistance oscillator for high-temperature operation. The oscillator employs an in-house 4H-silicon carbide BJT, integrated with the required circuit passives on a low-temperature co-fired ceramic substrate. Measurements show that the oscillator operates from room temperature up to 400 • C. The oscillator delivers an output power of 11.2 dBm into a 50 load at 25 • C, which decreases to 8.4 dBm at 400 • C. The oscillation frequency varies by 3.3% in the entire temperature range. The oscillator is biased with a collector current of 35 mA from a 12-V supply and has a maximum dc power consumption of 431 mW.

Efficiency Comparison of 2-Level SiC Inverter and Soft Switching-Snubber SiC Inverter for Electric Motor Drives

“…The turn-off of the bottom swich S x,b will occur in a similar way. In state two the commutation inductance L ξ and snubber capacitor C sx,t form a resonant circuit, thus the second-order differential equation can be written in (5). The solution of the (5) is given in (6), where ω r = 1/ L ξ C sx,t is the resonant frequency, Z r = L ξ /C sx,t is the damping factor, V Csx,t,0 is the initial voltage of the capacitor C sx,t and I L0 is the initial current of the commutation inductance L ξ .…”

“…For this reason, being able to integrate components like inductors and capacitors, it is now possible to maximize the power density of the power conversion system. Furthermore, SiC power semiconductors present higher voltage-blocking capability and lower on-state resistance compared to silicon based power semiconductors, as well as several benefits related to thermal management, so they are perfect for high temperature applications [4][5][6]. Particularly, given that the SiC power semiconductors can operate at extremely high junction temperatures, it is either possible to increase the power density of the whole converter system by decreasing the size of the heatsink, or to reach higher voltage applications without the need to enlarge the heatsink.…”

A 4H-SiC CMOS Oscillator-Based Temperature Sensor Operating from 298 K up to 573 K

“…4H-polytype silicon carbide semiconductor material is widely used for high temperature applications [ 1 , 2 , 3 ], and the possibility to fabricate integrated circuits (ICs) allows for an extension of its application fields. Up to now, both unipolar and bipolar 4H-SiC IC technologies have been developed: on bipolar technology, a Bipolar Junction Transistor based on multi-epitaxial stacks is used in analog [ 4 , 5 , 6 ] and digital [ 7 ] ICs, and its performance has been demonstrated up to 873 K. The 4H-SiC Complementary Metal Oxide Semiconductor Field Effect Transistor, CMOS technology proposed by Raytheon, has been developed, and analog and digital building blocks have been fabricated [ 8 ], such as, for example, a Positive-To-Absolute-Temperature (PTAT) circuit in the range between 298 K and 573 K, and with a maximum deviation from the ideal linear curve of [ 9 ]. Recently, Fraunhofer IISB provided a 4H-SiC 2 m-CMOS technology [ 10 ] and several ICs have been proposed, like CMOS Complementary-To-Absolute-Temperature (CTAT), a sensor in the range between 298 K and 438 K and with a sensitivity of 7.5 mV/K [ 11 ], or a temperature sensor based on a p-n diode from 297 K and 873 K, with an of the voltage-temperature characteristic.…”

Parameters identification for the nonlinear systems via target system-based method with intermittent adjustment

“…Introduction. Nonlinear systems are widely studied in the fields of natural and industrial engineering technology, such as negative resistance oscillators in electric circuits [11], artificial neural networks simulating biological structures [18] and so on. The phenomena of chaos, bifurcation and strange attractors of nonlinear systems are increasingly of interest to scholars, making their applications in the fields of biology [32], chemistry [9,26], meteorology [21], economics [23], physics [34] and engineering technology [20] more widespread as well.…”