This is a polyphase code modulation format used for pulse compression.
The default Frank code Code Order is N = 4.
The Frank Code has N2 elements and is defined as:
i,j
Where i and j range from 1 to N. For example, the Frank Code with N = 4, by taking phase value modulo 
is given by the following sequence:
0
0
0
0
4x4
0
0
0
0
The figure below shows the spectrum of a 10 us pulse using Frank Coded phase modulation, where N = 10.
