The study on shielding methods to electromagnetic radiation from DC electronic motor in HAPS

The electromagnetic compatibility (EMC) problem of high altitude platform systems (HAPS) is studied in this paper. A physical model for electromagnetic interferences (EMI) of electromagnetic radiation of spark discharge in DC electric motor is proposed. Based on this model, EMI frequency points has been estimated by equation approximatively for the given structure and size of a motor. Two methods are taken to shield electromagnetic radiation, the 1st one is to mount a perfect conductor block near the DC electric motor (EMI source), which results in the voltage magnitude falling 20 ∼ 37dB in antenna ports. The 2nd one is to mount a perfect conductor board near the antenna array (sensitive element), and the voltage magnitude of antenna ports falls 5dB at least. Both are valid to shield electromagnetic radiation, but the method to mount a perfect conductor block near the EMI source is more effective.