通信系统中的方向图可重构天线研究

发布时间：2019-01-26 15:24

【摘要】：近年来,随着无线通信技术的迅猛发展,系统对天线性能的要求越来越高。传统天线由于性能固定,在很多场合下难以满足要求。方向图可重构天线可改变方向图特性以适应周围环境的变化,从而改善接收端信噪比,提高系统容量,有广阔的应用前景。本文的研究主要包括以下三方面的内容。第一,提出了一种宽带方向图可重构渐变缝隙天线,通过改变4个p-i-n二极管的偏置电压可实现4种端射方向图,偏置电路简单,反射系数小于 10dB的公共频带为1.57GHz-3.31GHz,相对带宽71.3%,各状态在2.4GHz中心频率时的增益均大于6.4dBi。将所设计的零折射率超材料结构加载在渐变缝隙中,在2.2GHz-2.6GHz的频带内,增益可以增加1.4dBi-1.7dBi。第二,提出了一种地板加载互补裂隙环谐振器(CSRR)的方向图可重构微带天线,利用不同类型辐射单元间的耦合来控制波束方向,是实现方向图可重构的一种新途径。通过改变加载在CSRR中射频开关的状态,可同时在E面和H面切换主波束方向,同轴线底馈与微带边馈两种设计可分别实现9种和6种方向图,天线的面积分别为0.82λ_0×0.78λ_0和0.73λ_0×0.78λ_0。将该可重构天线组成四元相控阵,与普通微带天线阵列相比,具有更大的扫描角度,更小的增益波动和更低的旁瓣电平。第三,利用差分进化算法设计了一种新型平面印刷波束扫描寄生阵列天线,通过改变加载在寄生单元中的电抗值可使波束方向在方位面内扫描。利用等效网络模型对天线建模,再用差分进化算法优化电抗值,优化过程中不需要进行大量的电磁全波计算,显著提高了优化效率。从理论上分析了网络参数对天线性能的影响。实验结果表明该优化设计方法准确而高效。
[Abstract]:In recent years, with the rapid development of wireless communication technology, the system demands higher antenna performance. Because of its fixed performance, the traditional antenna is difficult to meet the requirements in many situations. The pattern reconfigurable antenna can change the pattern characteristics to adapt to the changes of the surrounding environment, thus improving the SNR of the receiver and increasing the system capacity, so it has a broad application prospect. The research of this paper mainly includes the following three aspects. First, a wideband pattern reconfigurable tapered slot antenna is proposed. By changing the bias voltage of four p-i-n diodes, four end-emitter patterns can be realized. The bias circuit is simple. The common frequency band with reflection coefficient less than 10dB is 1.57 GHz ~ 3.31 GHz, and the relative bandwidth is 71.3 GHz. The gain of each state at the central frequency of 2.4GHz is greater than 6.4 dBi. When the designed zero-refractive index metamaterials are loaded into a gradient slot, the gain can be increased by 1.4 dBi-1.7 dBiin the frequency band of 2.2GHz-2.6GHz. Secondly, a new pattern reconfigurable microstrip antenna for the floor-loaded complementary fissure ring resonator (CSRR) is proposed. The beam direction is controlled by the coupling between different radiation elements, which is a new way to realize the reconfigurable pattern. By changing the state of RF switch loaded in CSRR, the main beam direction can be switched between E plane and H plane at the same time. The two designs of coaxial line bottom feed and microstrip edge feed can realize 9 kinds of pattern and 6 kinds of pattern, respectively. The antenna area is 0.82 位 _ 0 脳 0.78 位 _ 0 and 0.73 位 _ 0 脳 0.78 位 _ 0, respectively. Compared with the conventional microstrip antenna array, the reconfigurable antenna has larger scanning angle, smaller gain fluctuation and lower sidelobe level than the conventional microstrip antenna array. Thirdly, a new plane printed beam scanning parasitic array antenna is designed by using differential evolution algorithm. The beam direction can be scanned in azimuth plane by changing the reactance value of the parasitic element. The antenna is modeled by the equivalent network model, and the reactance is optimized by the differential evolution algorithm. In the optimization process, there is no need for a large number of electromagnetic full-wave calculations, so the optimization efficiency is improved significantly. The influence of network parameters on antenna performance is analyzed theoretically. The experimental results show that the optimal design method is accurate and efficient.
【学位授予单位】：上海大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TN820

【相似文献】