Measurement of 4 GHz Radio Altimeter Interference Path Loss Including 5G Sub-6 Frequency Bands Using Beechcraft B300 Aircraft

The interference path loss (IPL) is the propagation loss of the signal power transmitted from the electric devices and that received at the avionics receiving port. IPL characteristics should be known to examine the coexistence condition of avionics and other electric systems. In this study, the 4 GHz radio altimeter IPL characteristics are measured using Beechcraft B300 aircraft. To cover the frequency band of the 5G mobile communication system, the measurement frequency band is set between 3.5 and 4.5 GHz. The measured minimum IPL values inside and outside the cabin are 67.5 dB and 47.7 dB, respectively, between frequencies 3.5 and 4.1 GHz.