Over the air measuring device , comprising: - N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ), wherein N > 1, - a measuring device , adapted to perform over the air measurements on a device under test , selectively using any one of the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ), and- a single guide rail , adapted to movably hold the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ), the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ) being independently movable along the single guide rail , characterized in that the over the air measuring device further comprises a single reflector reflecting signals transmitted by the device under test to the single antenna and/or reflecting signals transmitted by the single antenna to the device under test ; the over the air measuring device is adapted to perform a measurement using only one of the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ) simultaneously and the single reflector , wherein the single guide rail comprises at least one feed antenna device storage area , adapted to store N-1 of the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ) side-by-side, during a measurement using one of the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ), and wherein the single guide rail comprises a single feed antenna device measurement location , adapted to hold one of the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ) during a measurement using said one of the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ). - N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ), wherein N > 1, - a measuring device , adapted to perform over the air measurements on a device under test , selectively using any one of the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ), and- a single guide rail , adapted to movably hold the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ), the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ) being independently movable along the single guide rail , the over the air measuring device further comprises a single reflector reflecting signals transmitted by the device under test to the single antenna and/or reflecting signals transmitted by the single antenna to the device under test ; the over the air measuring device is adapted to perform a measurement using only one of the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ) simultaneously and the single reflector , wherein the single guide rail comprises at least one feed antenna device storage area , adapted to store N-1 of the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ) side-by-side, during a measurement using one of the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ), and wherein the single guide rail comprises a single feed antenna device measurement location , adapted to hold one of the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ) during a measurement using said one of the N feed antenna devices (6, 6 1 , 6 2 , 6 3 , 6 4 , 6 5 , 6 6 , 6 7 , 6 8 ). <EOS>