A Design Of Wireless Terminal Antenna And Frequency Selective Radom

The development and application of wireless communications technology play an important role in modern communication. Undoubtedly, antenna is an indispensable part in communication system, and its performance relates to the quality of communications. As an important part of modern air-craft, warship and radar on the ground, radome is no only used for protecting antennas, but also widely applied in stealth technology, which has a new vitality and development in the future and is becoming one of the hot topic of modern electromagnetic researches.The characteristics of multi-band, miniaturization and wideband technology of antenna have drawn more and more attention in recent years. Two novel designs suited for applying in WLAN (Wireless Local Area Network) have been proposed and the antennas have been constructed and tested. One is"Motorola"shaped dipole, and the other one is"scarecrow"shaped monopole. The two antennas were simulated, constructed and tested. The simulated and measured results show that the proposed antennas achieved good characteristic of tri-band and omni-directional at H-plane and the gain is about 3dB.The radome with frequency selective surface (FSS) technology allows the incident energy fully transmitted at resonant frequency of FSS, and completely reflected out-of-band electromagnetic waves, within working band the band-pass character appears. Meanwhile the electromagnetic waves could be scattered in other directions by conformal special shape radome, which not only greatly reduces the out-of-band interference with radio equipment, but also effectively reduces the out-of-band radar cross section (RCS) of antenna systems. Two types of FSS radome were designed for navigation antennas. The element shape of the FSS was improved hexagon-(conventional hexagon and interdigitated hexagon). The improved hexagon reduced area of FSS element, therefore finite FSS could admit more elements. The FSS radome were constructed and tested, and the results meet our design goals.Finally, the navigation antenna and FSS radome system is analysed by CST commercial electromagnetic simulator. The radiation patterns and VSWRs are obtained in three different distances with and without FSS radome.