基于串并联结合馈电的高增益垂直极化全向天线

A high gain vertically polarized ominidirectional antenna based on series-parallel fending method

采用基于串并联结合馈电的方法设计了一种高增益垂直极化全向天线。采用印刷偶极子天线作为基本辐射单元;将4个该基本辐射单元组成串馈阵列以提高天线增益;为进一步提高天线增益和改善串馈阵方向图的频偏特性,将两个四元串馈阵列并联起来,并通过微带线从并联中心馈电;最后将金属支撑与微带馈电网络对称设计,实现良好的馈电和改善水平面方向图的不圆度。制作了天线实物并进行了测试,实物的测试结果表明,天线在7.4 GHz~8.4 GHz的频段内VSWR≤2,阻抗带宽为13%。在工作频段内天线方向图不圆度小于2.5 dB,增益大于8 dB。此外,天线的横向尺寸小于0.7λ0。该天线结构紧凑、加工方便、性能优良,可应用于宽带、高增益、全向空域覆盖的通信系统中。

A vertically polarized omnidirectional antenna with high gain is proposed based on the method of series-parallel feeding.Firstly,a printed dipole antenna is used as the basic radiation unit,and then four of the basic radiation units are formed into a series-fed array to improve the antenna gain.Secondly,in order to further increase antenna gain and make the antenna patterns of the series-fed array desensitize to frequency,two four-element series-fed arrays are connected in parallel and fed from the center through a parallel feed network.Finally,the metal support and the microstrip feeding network are symmetrically designed to achieve good feeding and improve the unevenness of the pattern in the horizontal plane.The antenna was fabricated and measured.The experimental results show that the impedance bandwidth of the antenna is 13%and the VSWR≤2 in the frequency range of 7.4 GHz~8.4 GHz.The gain variations in the horizontal plane less than 2.5 dB and the gains are more than 8 dB across the operating band.In addition,the transverse size of the antenna is less than 0.7λ0.The antenna has the advantages of compact structure,convenient processing and excellent performance.It can be used in wide-band,high-gain and wide-angle space coverage communication systems.