| As a key component of conmunication systerm, antenna plays the role of traslating the current signal to electromagnetic wave signal. Today, the bandwidth of communication systerm becomes wider and wider. It is impossible to install several antennas in limit space, so it has been developed into a vital important branch to research the utral wideband antenna.Nowadays, the Air Defence Radar become diversity, its working frequency range from a few GHz to several tens of GHz. Therefore, the direction finding antenna of the Anti Radiation Missile also needs to cover the frequency band as much as possible. For the special application of the anti radiation missile, there are some special requirements for the antenna, such as the end radiation, the limited size, the antenna conformal anrry mounted to the missile, space lever cover, etc.. Traditional antenna has been unable to meet the requirements. Under the supports of the State Key Laboratory Foundaion"Research of Endfire Conformal Direction-finding Antenna Array”, we designed a substrate intergrated waveguide based ultra wideband H plane horn antenna in this paper. The bandwidth of the is 6GHz-18 GHz while the antenna has the advantages of wideband, high gain, low profile, good end radiation characteristics.The main research work and innovations of this thesis are listed as follow:1. The single ridge ultrawideband SIW-based endfire antenna was designed. The wideband conversion structure of coaxial antenna SMA connector to the substrate integrated waveguide was intruduced. The elliptical transition structure patch was proposed to improve the match performance from the horn aperture to free space. The step ridge structure was used to improve the bandwidth of the antenna.2. The SIW based with double-ridged endfire ultra wideband antenna was designed. The gradually increases air hole was proposed to slow the transition from the dielectric slab to free space. Two symmetrical bending slots was used to uniform the electromagnetic waves phase. As a result, the bandwidth of the proposed antenna was6GHz-18 GHz while the gain at the endfire direction was more than 4.5dB.3. The SIW based ultra wideband end-fire conformal antenna array was designed.The effects of metal cylinder to antenna array radiation characteristics and the mutual coupling between antenna elements. The phenomenon of electromagnetic wavestranslate through the radome was analysised, and the influence of media radome to antenna radiation characteristics was researched.The proposed SIW based ultra wideband antenna working in the 6GHz-18 GHz band had achieved the 4.5dB gain at the endfire direction, while the overall thickness of the antenna was only 4mm. Because of the large conducting plane installed in the antenna unit design, the antenna had good resistance to metal performance when the antenna was installed on the metal body, and the influence of the missile body to the antenna unit was very small. At the same time, the performance of the array was analyzed, and the parameter analysis will effective to guide the design of conformal array. The designed antenna could be applied to end-fire array conformal finding,anti-radiation missiles DF arrays and other occasions. At the same time, the designed antenna unit had reference value for antenna installed metal surface, it is possible to provide a reference for the wideband direction finding array which was installed on metal cylinder surface. |
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