Extraction of thermal time constant in HBTs usingsmallsignal measurements

Abstract

A novel method for finding the thermal time constant of HBTs is proposed. It utilizes small signal measurements in the frequency domain of the typical negative differential resistance found in the active region, i.e., normal bias conditions for the device. In this way, non-linearities in the thermal resistivity does not disturb the extraction and the device needs only to be characterized in one bias point.

Dynamic thermal characterization and modeling of packaged AlGaAs/GaAs HBTs

“…This paper was recommended for publication by Associate Editor D. Blackburn upon evaluation of the reviewers' comments. This work was supported by the Consiglio Nazionale delle Ricerche (CNR) through the MADESS or as an indicator of the junction temperature and can be split into CW [2]- [5], and pulsed [6] or small-signal [7] techniques. Quite less frequent are the examples of HBT dynamic thermal characterization, i.e., one that accounts for the time dependence of self-heating [8] although a few methods, typically based on theoretical calculations [9] or the analysis of the thermal step response, have been tested on different kinds of semiconductor devices [10]- [12].…”

Thermal characterization of light‐emitting diodes in the frequency domain

“…In this case, increasing frequency of harmonically modulated power input results in the variation of the wave form phase and modulation depth of the temperature-sensitive parameter due to finite thermal relaxation time. The advantages of the frequency-domain method were demonstrated in thermal analysis of silicon-on-insulator metal-oxidesemiconductor field-effect transistors [8] and heterojunction bipolar transistors [7].…”