and u03c6 34 are made across the antenna for each bsn4 phase setting l 1 represents the phase delays in the path connecting the antenna element j 1 to the receiver port for channel 1 ra represents the receiver phase delay in the path connecting the receiver port for channel 1 to one side of u03c6 12 phase detector this same labeling convention is used for the other similar situationed blocks m 12 represents the phase delay of the mutual coupling between the antenna elements j 1 and j 2 actually what is of interest is the phase of mutual coupling that is the phase shift or phase delay or time delay from one element to another of a signal radiated from one element to another the measured phases are combined in such a way that the cross coupling errors introduced on m 23 for example cancel and the resultant phase response is a linear curve the linearized resultant phase is finally compared with the phase detector center of m 23 to determine the value of bsn4 which phase matches elements 1024 and 1021 elements u03c6 23 u03c6 23 u03c6 12 u03c6 12 _ u03c6 34 u03c6 34 _ u03c6 23 is the measured phase at 1022 1023 phase detector u03c6 12 is the measured phase at 1021 1022 phase detector u03c6 34 is the measured phase at 1023 1024 phase detector u03c6 23 with hat is the corrected.