Determining excitation coefficients of dual-frequency shaped beam linear array antennas for mobile base station

The sidelobe level increase of a dual-frequency linear array antenna is numerically analyzed from the viewpoint of base station antenna design. The analysis results suggest the following: frequency separation and element spacing can be determined for target tilt angle to avoid sidelobe increase caused by the influence of grating lobes. The sidelobe increase created by phase distribution error is shown throughout the frequency band. It is shown that the increase is more critical at the lower frequencies. A method of determining optimum excitation coefficients is proposed.<>