Abstract: A compact phasing transmission having an infinitely variable adjustment to the relative phases between the input shaft and output shaft of the transmission is disclosed. A harmonic drive pancake gear set is incorporated between the input shaft and output shaft of the transmission. A pancake motor is enclosed within the phase transmission and is coupled to the harmonic drive pancake gear set to provide input to the wave generator of the harmonic drive. The intermeshing of the pancake motor and harmonic drive between the input shaft and output shaft of the phasing transmission will cause the two shafts to rotate at the same speed. When the pancake motor is activated, the wave generator of the harmonic drive gear set will rotate thereby varying the phases between the input shaft and output shaft of the phasing transmission.