Technique for estimating the radiated emission of an integrated circuit in a TEM-cell under temperature exposure

Annotation: The integrated circuits (IC) used in radioelectronic devices cre-ate electromagnetic radiation, the level of which is analyzed while ensuring electromagnetic compatibility. In real-world operating conditions, the radioelectronic devices are exposed to temperature, that affects the amplitudes and the frequencies of the radiated emission of the IC. This paper proposes a technique and an algorithm to measure the level of radiated emissions of IC at a given temperature. Using the technique, the levels of radiated emissions of the K1986VE91T microcontroller were measured in a frequency of 150 kHz – 1 GHz and the tempera-tures from –50 to +150 °C ranges. It is shown that at the main clocking frequency, around 80 MHz and the 2nd harmonic, the effect of temperature does not affect the level of radiated emis-sion of the microcontroller and the change is no more than ± 0.3 dB. The operation of various microcontroller units with an in-crease in its temperature from minus 50 to +150 °C reduces by 5.5 dB the maximum level of radiated emission of the micro-controller in the frequency range of 8–27 MHz. The most tem-perature-dependent levels of radiated emission are observed up to the 6th harmonic of the clock frequency of the microcontroller and reach 35.8 dBμV, which is 5.7 dB higher than the meas-ured level at normal temperature.

Keywords: integrated circuit, radiated emissions, tem-cell, electromagnetic compatibility