| In satellite communication, circularly polarized antenna are widely used as send/receive antenna. In order to meet the requirements under various conditions, a variety of circularly polarized terminal antenna have been developed.In this thesis, some key technologies of terminal antenna are summarized. By bending the radiator and using coupling feed, a compact planner circular polarized antenna is designed. Multi-stage cascade feed network is designed with introduction of new coupled-line coupler structure, and a four-fed compact broadband circularly polarized antenna is presented. Using new plane dipole array, combined with six-sided cone monopole structure, a broadband dual-polarized omni-directional antenna is proposed. The software CST is used in antenna simulations. Proposed antenna are produced through printed circuit board and machining, and antenna performance are tested in Satimo anechoic chamber.Work and achievements of this thesis is mainly reflected in the following aspects:(1)A compact planner circular polarization antenna is realized which works in Beidou satellite band. The maximum size of the antenna is only0.13λ0, it is really a considerable advantage in the field of small circularly polarized antenna.(2)A novel compact coupled-line structure3dB coupler is proposed, and it is used in the design of feed network. A compact wideband circularly polarized antenna is presented to achieve stable circular polarization gain. This antenna structure could to be applied in multiple frequency bands, such as the UHF band, L-band, S-band, RFID band and the like.(3) A novel broadband omni-directional dual polarized antenna is proposed, covering not only the mobile satellite communications band1980-2200MHz, but also covering the existing2G,3G and LTE band. This structure not only can be used in satellite communications, but also in common mobile communications. |
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