Isothermal Electrical Characteristic Extraction for mmWave HBTs

In this brief, we demonstrate a straightforward approach to obtain isothermal electrical characteristics of state-of-the-art SiGe:C BiCMOS heterojunction bipolar transistors designed for mmWave applications. DC and conventional continuous-wave RF measurements are performed at different chuck temperatures (
$T_{\rm chuck}$
). Knowing the thermal resistance (
${R} _{\rm {TH}}$
) of the device, all the isothermal dc and ac (above thermal cutoff frequency) data can be determined. The validation of the methodology is demonstrated by comparing the results with the pulsed dc and pulsed RF measurements, which are found to be in good agreements. This method could be applied with a standard measurement equipment.