X波段高增益微带阵列收发天线的设计与实现

发布时间：2018-06-26 03:07

本文选题：微带阵列天线 + 高增益　；参考：《电子科技大学》2015年硕士论文

【摘要】：与传统天线相比,微带天线具有低轮廓,重量轻,易于共形,易于集成等许多优势。这使它在卫星导航和卫星通信方面获得了普遍应用。在要求低剖面辐射的情况下,微带天线总是被优先考虑使用。但由于微带天线具有功率小、工作频带窄、功率损耗大等缺点,这些在很大程度上都约束了其应用范围。最近这些年来,天线研究者们着力于寻找具有宽频带、高增益、小型化、多频段等优良特性的天线。所以,研究如何使微带天线具有高增益特性是一个很有实际意义的课题。本文是通过阵列的方式来增加微带天线的增益。本文设计了一个X波段的收发天线相互独立的高增益雷达探测天线。天线和收发机电路设计在同一块金属板上。馈电方式采用同轴线馈电。同轴线穿过金属板将收发机电路和天线连接起来,由于射频电路与天线被金属板隔开,射频电路对天线的辐射基本无影响。发射天线和接收天线之间也使用金属板隔开,这样保证了发射天线和接收天线之间的隔离度。同时对收发天线而言,金属板还充当了反射板,可使辐射出的电磁波方向性更强,提高了天线的增益。从仿真实验可以看出,增加金属板后天线的增益提高了3dB。收发天线都是20个单元的直线阵,采用串行馈电的方式。使用一个T型功分器与同轴线相连。矩形微带天线阵元的间距设为一个传导波长。这样确保了每个阵元接收的馈电电流同相,有利于提高天线阵的增益。为了提高主瓣电平同时抑制副瓣电平,本文采用切比雪夫综合法来计算每个阵元馈电电流的幅度,然后根据电流的幅度推导出每个阵元馈电微带线的宽度。电流由直线阵的中间向两边一级一级的传输。每级之间都有一个四分之一波长阻抗变换器,这样可以使得总的反射电流最小,从而提高天线阵的辐射效率。本文设计的天线的谐振频率为9.6GHz,带宽为150MHz,增益达到22dB,水平方向上的半功率波瓣宽度为5.2度,副瓣电平抑制到-25dB以下,前后比小于-30dB。在工作带宽内收发天线的隔离度大于57dB。达到了雷达探测天线的要求。
[Abstract]:Compared with traditional antenna, microstrip antenna has many advantages, such as low profile, light weight, easy conformal and easy integration. This makes it widely used in satellite navigation and satellite communication. Microstrip antennas are always preferred when low profile radiation is required. However, the microstrip antenna has many disadvantages, such as low power, narrow working band and large power loss. In recent years, antenna researchers have focused on finding antennas with broad band, high gain, miniaturization, multi-band and so on. Therefore, the study of how to make microstrip antenna have high gain characteristics is a very meaningful topic. In this paper, the gain of microstrip antenna is increased by array. In this paper, an X band high gain radar detection antenna is designed, which is independent of each other. The antenna and the transceiver electromechanical circuit are designed on the same metal plate. The feeding mode adopts coaxial line feed. The coaxial line passes through the metal plate to connect the transceiver electromechanical circuit and the antenna. Because the RF circuit is separated from the antenna by the metal plate, the radiofrequency circuit has no effect on the radiation of the antenna. A metal plate is also used between the transmitting antenna and the receiving antenna, which ensures the isolation between the transmitting antenna and the receiving antenna. At the same time, the metal plate acts as the reflector, which makes the electromagnetic wave directivity stronger and the antenna gain higher. The simulation results show that the gain of the antenna increases by 3 dB after the metal plate is added. The transceiver antenna is a linear array of 20 units. A T-type power divider is used to connect to the coaxial line. The spacing of rectangular microstrip antenna array is set to a conduction wavelength. In this way, the feed current received by each element is in phase and the gain of antenna array is improved. In order to improve the main lobe level and suppress the sidelobe level, the Chebyshev synthesis method is used to calculate the amplitude of each element feed current, and the width of each element feed microstrip line is derived according to the amplitude of the current. The transmission of electric current from the middle of a linear array to one level on either side. There is a 1/4 wavelength impedance converter between each stage, which minimizes the total reflected current and improves the radiation efficiency of the antenna array. The resonant frequency of the antenna designed in this paper is 9.6 GHz, the bandwidth is 150 MHz, the gain is 22 dB, the width of the half power lobe in the horizontal direction is 5.2 degrees, the sidelobe level is reduced to less than -25 dB, and the ratio between front and back is less than -30 dB. The isolation of transceiver antenna is greater than 57 dB in the working bandwidth. Meet the radar detection antenna requirements.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN822

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