Analysis of the Induced Currents and Blindness in a Dipole/Slot Phased Array

The phases and amplitude of induced currents on the surface of the elements in a phased array are analyzed. The phase distribution of the induced currents in the phased array depends on the arrangement of the elements. For a dipole array, the phase difference between the excited element and its nearest elements is determined by e^-jkr when the elements are in tandem arrangement, whereas in the parallel arrangement, the phase difference is determined mainly by e^-jkr and the imaginary unit j. The same phenomenon is also observed in a slot array. This study investigates why the phase difference differs between parallel and tandem array arrangements. The active patterns of the excited element are simulated and analyzed. The phases and amplitudes of the induced currents may explain how mutual coupling affects the active patterns in the phased array. In particular, the phases of the induced currents play a critical role in whether the blindness appears.