The advantage of the promising method of passive radiosensor technical diagnostics (PRTD) over the currently existing methods for determining the technical condition (vibrometry, thermal control, JTAG-testing, optical control) are: no inertia, no processor time, no galvanic contact with the object of study. In modern scientific literature, almost no attention is paid to numerical models of electronic devices, including those based on bipolar transistors (BPT), which describe the process of oscillatory redistribution of energy and radiation used in PRTD. Therefore, the purpose of this study is to develop the PRTD method through the development, analysis and comparison of circuit and electrodynamic models of oscillatory energy redistribution in the BPT. The paper presents and analyzes simplified circuit and electrodynamic models of oscillatory redistribution of energy in the BPT. The parameters of the models are calculated signal radio profiles (SRP) are obtained for the electrical component of electromagnetic radiation created by the radio-electronic unit itself, built on the BPT. Methods for adjusting the reference parameters depending on the actual conditions for switching on the BPT are shown. It has been established that the cross-correlation function of the SRP obtained as a result of circuit and electrodynamic modeling is not lower than 0.93, which indicates a high similarity of the presented models. In practice, the use of the developed models in the analysis of SRP obtained by recording the intrinsic emissions of radio engineering components of electronic devices will allow us to determine the operating mode of the BPT and its speed with a sufficiently high accuracy. This analysis can be used in the PRTD, indicating a malfunction of the signal circuits, or degradation of the parameters of the element itself in the early stages
