Reconfigurable Antenna With Elevation and Azimuth Beam Switching

A reconfigurable microstrip antenna is proposed for low-cost adaptive beam-switching applications. A small patch-slot ring structure is used as the radiating element where an asymmetrical arrangement of p-i-n diodes is employed to switch the pattern in four directions. The antenna provides pattern switching of 65?? and 45?? in its fundamental mode for the elevation and azimuth planes, respectively. By maintaining the resonant frequency and beamwidth as relatively constant, beam switching is realized using a single feed point.