基于宽波束磁电偶极子天线的宽角扫描线性相控阵列

设计并加工了两款基于宽波束磁电偶极子天线单元的宽角扫描线性阵列.首先,通过加载磁偶极子的方法拓展了天线单元的3-dB波束宽度.然后,基于该宽波束天线单元设计了两款具有良好宽角扫描特性的一维阵列天线.实测结果表明,天线单元的E面方向图3-dB波束宽度在9GHz—12 GHz均大于107°,H面方向图3-dB波束宽度在7GHz—12 GHz均大于178°.E面阵列中心单元的有源驻波比在9GHz—13 GHz小于2,相对阻抗带宽为36.36%.H面阵列中心单元的有源驻波比在9.6GHz—12.6 GHz小于2.5,相对阻抗带宽为27.03%.E面阵列在9GHz—12 GHz可实现±70°的有效宽角扫描.H面阵列在9GHz—GHz可实现±90°的有效宽角扫描.与传统的扫描阵列相比,设计的阵列可实现有效宽带宽角扫描,在X波段相控阵雷达方面具有广阔的应用前景.

Wide-angle scanning linear phased arrays based on wide-beam magneto electric dipole antenna

Microstrip phased array has aroused interest of many researchers because of its beam agility.However,a big problem for typical microstrip array is that its main beam can only scan from about–50°to 50°,with a gain loss of 4-5 dB.Meanwhile,the relatively narrow operating bandwidth of microstrip antenna is also a problem in application.These flaws have dramatically limited its applications and spawned many studies on phased array with wide-angle scanning capability.Several methods have been proposed to broaden the scanning coverage of phased array,such as utilizing pattern-reconfigurable antenna as an element of array,taking wide-beam antenna as the element of array,and adopt metasurface as the top cladding of array.However,most of existing researches mainly focus on achieving wide-angle scanning performance within a relatively narrow bandwidth.A phased array that possesses wide-angle scanning capability at both main planes within a relatively wide bandwidth is highly desirable.In this paper,a wide-beam magnetoelectric(ME)dipole antenna is proposed.It consists of an ME dipole antenna in the form of microstrip patch and a pair of magnetic dipoles.Metallic through holes integrated with patches and ground are utilized to form magnetic currents.Extra magnetic dipoles are added to broaden the 3-dB beam-width.The simulated results reveal that the 3-dB beam-width of the proposed antenna is greater than 107°in the E-plane(9 GHz–12 GHz)and 178°in the H-plane(7 GHz–12 GHz)respectively.The impedance bandwidth of the proposed antenna is 53.26%from 7.3 GHz to 12.6 GHz(VWSR<2).Based on the proposed antenna element,two linear phased arrays are fabricated and measured.To test the wide-angle scanning capability of the arrays,each antenna element is simply fed with alternating currents with identical amplitude and linearly increasing phases.The measured results reveal that the wideangle scanning capability of H-plane array and E-plane array can be obtained from 9 GHz to 12 GHz.The scanning beam of the H-plane array can cover the range from-90°to 90°.The scanning beam of the E-plane array can cover the range from–70°to 70°.The impedance bandwidth of the central antenna is 27.03%for the H-plane array from 9.6 GHz to 12.6 GHz(active VWSR<2.5)and 36.36%for the E-plane array from 9 GHz to 13 GHz(active VWSR<2)respectively.Hence,the proposed method can be used as a reference for designing a wide-beam antenna and wide-angle scanning phased array and the designed phased arrays can be applied to X-band radar systems.