FIRST RESULTS OF THE W AND Q-BAND BEACON MEASUREMENTS WITH A LEO CUBESAT

The ITU has assigned the W-band for the downlink and uplink of satellite communications systems. This was highly necessary because the capacities provided by the new generations of high throughput satellites (HTS) are in the order of TBit/s, both uplink and downlink, requiring wider bandwidths. The W-band, together with the Q-band, will be employed by the feeder links of the next generation of HTS. The Q-band is already under detailed analysis (e.g. Alphasat TDP5) and is being used by the first satellites. However, the W-band lacks real measurements between space and ground to get an accurate channel model. ESA has started the initiative for the exploration of this band by giving to the consortia composed of VTT Technical Research Centre of Finland, KuvaSpace, LCTechnologies, Fraunhofer IAF, the University of Stuttgart, the Catholic University of Louvain, and with the project lead by JOANNEUM RESEARCH the opportunity to build and operate a 3U CubeSat which transmits beacons at 75 and 37.5 GHz, both with left and right-hand circular polarization. This system allows to derive the complete transfer matrix and the frequency scaling relation between the two bands. The satellite was launched in June 2021 and soon afterwards a 75 GHz beacon was transmitted, for the first time worldwide, from space to ground. In this paper we describe the architecture of the system and the methods to measure the beacon. First results are presented, allowing to perceive the different attenuation between W and Q-band. Challenges faced throughout a wave propagation campaign with L​E​