Mobile propagation measurements in the US at 20 GHz using ACTS

Results are presented for four propagation measurement campaigns involving a mobile receiving laboratory and 20 GHz transmissions from the Advanced Communications Technology Satellite (ACTS). The 1994 campaigns were executed during weekly periods in and around Austin, Texas in February and May (elevation=55°), in Central Maryland during March (elevation=39°), and in Fairbanks, Alaska and environs in June (elevation=8°). The measurements tested the following effects at 20 GHz: (1) attenuation due to roadside trees with and without foliage, (2) multipath effects for scenarios in which line of-sight paths were unshadowed, (3) fades due to various types of terrain and roadside obstacles, (4) fades due to structures in urban environs, and (5) single tree attenuation. Each of the four field tests, which were conducted during the first six months of 1994, consisted of five contiguous days on which approximately four hours of measurements were made. Field tests were undertaken in Austin, Texas and nearby suburban and rural environs in February when deciduous trees were bare, and during May when they were in full blossom. In March, tests were made in Central Maryland (bare deciduous tree period) along the same system of roads where mobile propagation measurements were previously made at UHF and L-band by the authors. The rationale for replicating the same system of roads in Central Maryland was to combine the results of previous measurements so that developed models could be extended to the K-band (20 GHz)