Beam scanning using the stacked microstrip antenna parameters

In conventional phased arrays external phase shifters are used to generate inter-element phase shifts, that cause the array beam to scan. The phase shifter insertion losses cause gain degradation and lower array efficiency. It is desirable therefore, to eliminate or reduce the phase shifter use by using alternative methods. In this paper, we propose a new technique to generate the required phase shifts by using resonant array elements and modifying their resonant frequencies. For microstrip antennas, the phase value can be changed by modifying the physical parameters, which in practice may be done by using reconfigurable patches based on microelectromechanical systems (MEMS) technology.