Long‐Term Propagation Measurements in Madrid in a Q‐Band Satellite‐to‐Earth Link

ABSTRACT The Q/V band (40/50 GHz) is gaining interest as satellite operators will need larger bandwidth to be able to provide their services, which are experiencing an increasingly high demand. An accurate characterization of the satellite‐to‐Earth propagation channel is of paramount importance to guarantee a high level of quality of service, by apportioning the right amount of resources to the users. For this reason, assessing the impact of the atmospheric effects in the band is critical. In Europe, the propagation payload of the Alphasat satellite has allowed the development of critical experiments in the Q‐band (39.4 GHz). One of these propagation campaigns was carried out in Madrid, Spain, from 2014 to 2026, resulting in more than 10 years of measurements gathered. The main results of Q‐band attenuation and rainfall rate from the processed 10 years of measurements of this ongoing experiment are presented in this paper. Moreover, rainfall rate, excess, total, and gas attenuation results, as well as the yearly variability of their statistical distributions, are quantified and compared to the predictions of the corresponding ITU‐R model. The results show that high values of attenuation are expected in time percentages relevant for the design of satellite links. For example, 20 dB of attenuation is exceeded for 0.04% of the time. Also, a large year‐to‐year variability can be expected for the temperate climate of Madrid.