Method to predict scan blindness in printed planar phased arrays

The scan blindness phenomenon is studied in relation with surface waves. The classical method of predicting the blind spot using surface wave circles does not include the loading effect of antennas on substrate. It is found that for some arrays with high substrate thickness this effect can be major. A method based on the effective propagation constant of surface wave is introduced. FDTD simulator is used to calculate the element pattern and the impedance of array elements while scanned. These results are compared with the beta calculations and the surface wave diagrams. In this paper, printed dipole is considered as the single element. The results can be extended to other types of printed antennas with the similar behavior, like microstrip patches.