TACAN is based upon the same principal as the conventional VORs using the rotating antenna to space modulate the carrier wave creating an AM signal. It rotates 6 times faster than the VOR to generate in theory, 6 times the accuracy. It is prone to a 60 degree error as the same phase relationship can occur at 6 different locations in one rotation. Because of the higher frequency used, it is not as prone to the propogation errors encountered on early VORs.
The range side of the TACAN is exactly the same as DME.