An Intermediate Frequency Amplifier for High-Temperature Applications

IEEE J. Electron Devices Soc.

Zumbro

et al. 2019

Self Cite

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.

Section: Design and Prototypingmentioning

confidence: 99%

Section: Design and Prototypingmentioning

confidence: 99%

See 1 more Smart Citation

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

IEEE J. Electron Devices Soc.

Zumbro

et al. 2019

Self Cite

“…The SiC BJT used in this work were fabricated on a 4-inch, 4H-SiC wafer with six epi-layers. More information on the device fabrication and HT characterization can be found in [8]. The BJT's S-parameters, required for the oscillator design, were measured for a collector current (IC) of 11 mA and a collector-emitter voltage (VCE) of 10 V. The magnitude of measured S-parameters from RT up to 300 ⁰C are shown in Fig.…”

Section: Device Fabrication and Characterizationmentioning

confidence: 99%

Silicon Carbide BJT Oscillator Design Using S-Parameters

Rodriguez

et al. 2019

MSF

Self Cite

Radio frequency (RF) oscillator design typically requires large-signal, high-frequency simulation models for the transistors. The development of such models is generally difficult and time consuming due to a large number of measurements needed for parameter extraction. The situation is further aggravated as the parameter extraction process has to be repeated at multiple temperature points in order to design a wide-temperature range oscillator. To circumvent this modelling effort, an alternative small-signal, S-parameter based design method can be employed directly without going into complex parameter extraction and model fitting process. This method is demonstrated through design and prototyping a 58 MHz, high-temperature (HT) oscillator, based on an in-house 4H-SiC BJT. The BJT at elevated temperature (up to 300 0C) was accessed by on-wafer probing and connected by RF-cables to the rest of circuit passives, which were kept at room temperature (RT).

“…For instance, at 10 mA, the decrease in g m from 25 • C to 500 • C is about 20%. More information on the fabrication process and the high-frequency performance of SiC BJTs can be found in our previous work on an HT amplifier design [11].…”

Section: Introductionmentioning

confidence: 99%

A 500 °C Active Down-Conversion Mixer in Silicon Carbide Bipolar Technology

IEEE Electron Device Lett.

Zumbro

et al. 2018

Self Cite

This paper presents an active down-conversion mixer for high-temperature communication receivers. The mixer is based on an in-house developed 4H-SiC BJT and down-converts a narrow-band RF input signal centered around 59 MHz to an intermediate frequency of 500 kHz. Measurements show that the mixer operates from room temperature up to 500 • C. The conversion gain is 15 dB at 25 • C, which decreases to 4.7 dB at 500 • C. The input 1-dB compression point is 1 dBm at 25 • C and-2.5 dBm at 500 • C. The mixer is biased with a collector current of 10 mA from a 20 V supply and has a maximum DC power consumption of 204 mW. High-temperature reliability evaluation of the mixer shows a conversion gain degradation of 1.4 dB after 3-hours of continuous operation at 500 • C.