Optimization of directivity for sleeve dipole array

The antenna gain is important for communication system. The gain is proportional to the directivity. For point to multi-points communication system, higher directivity is required. The sleeve dipole array is commonly used for this application. Unfortunately, the aperture efficiency will not increase for more antenna dipole elements at sleeve dipole array. This is due to the taper amplitude distribution at the sleeve dipole array. This paper, sleeve dipole array with higher directivity is designed for IEEE802.11a WIFI communication system. With optimization of amplitude distribution by using GEMS, the directivity of four elements sleeve dipole array is increased from 7.5 dBi to 7.9 dBi. The test results are agreed with that of the simulations.