Deviation of the approximate angle-independent pattern with frequency diverse array antenna

The wavelength array (WA) originating from the frequency diverse array (FDA) can achieve strictly angle-independent pattern. But when WA is simplified to a basic FDA, the produced pattern can not be angle-independent any more, which is investigated in this paper. We adopt a basic FDA as transmitter and observe its pattern at an appropriate reference range. The observed pattern is modulated periodically in range except for a slight deviation, which has been analyzed mathematically. Several impact factors are indicated for reducing the range deviation. Finally, some numerical simulations are given to verify these results. Since array error is inevitable, our analysis provides a basis for array design in practical application of FDA.