Generation of OAM Radio Waves Using Circular Vivaldi Antenna Array

Table 2

Distinguishing rules.

Phase delay	𝑛	Judgment: 𝑙
B after A	2	+1
A after B	2	−1
B after A	4	+2
A after B	4	−2
B after A	6	+3
A after B	6	−3

𝑙=0 and 4 cannot be judged in this condition.