| 摘要 |
PURPOSE:To suit the side band directional pattern of a single frequency wide aperture antenna to an ILS localizer by determining the current distribution ratio between the even number of elements through weighting. CONSTITUTION:A directional pattern is adjusted by the mean value method from the formulas of directional pattern EN and current distribution factor An of an array antenna. By repeating the mean value method (m) times, a new directional pattern ENm with small side lobe and small beam oscillation is obtained. To realize a required side band directional pattern, a function of a main beam is selected and a current distribution factor determined by converting the function through Fourier conversion is weighted. The weighting factor is based on a sine function. Consequently, an array antenna suitable for a localizer having an effective course structure can be realized under airport conditions easy to generate radio wave troubles in a single frequency system. |
