Design of a wide-angle scanning tightly coupled dipole array element
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摘要: 提出一种新型紧耦合偶极子阵列天线单元,并结合等效电路对天线参数进行分析与优化。引入频率选择表面置于天线口径上方,取代传统的电介质板,用以改善宽角扫描时阻抗变换。巴伦采用微带线到共面平行双线过渡结构,实现平衡馈电及阻抗变换。仿真结果表明,该阵列能够实现3倍频(2~6 GHz) E面80°、H面45°的波束扫描,且在扫描范围内有源驻波比均小于3。仿真得到的阵列法向交叉极化隔离度保持在25 dB,由于阻性FSS的损耗,天线增益有所下降。该天线结构简单紧凑,易于加工制作,实现了紧耦合阵列的小型化。Abstract: The paper proposes a novel tightly coupled dipole array antenna element design, and combines the equivalent circuit to analyze and optimize antenna parameters. The design introduces frequency selective surface placed above the antenna aperture to replace the traditional dielectric superstrate for wideband and wide-angle impedance matching. The balun employs microstrip to coplanar parallel two-wire transition structure to achieve balanced feed and impedance transformation. A prototype is simulated and the results show that the design provides a 3∶1 (from 2 GHz to 6 GHz) bandwidth while scanning to 80° in E-plane and scanning to 45° in H-plane, with an active VSWR < 3. Besides, the cross-polarization isolation of the array at broadside is kept at 25 dB, but the antenna gain is reduced due to the loss of the resistive FSS. The antenna has a simple and compact structure, easy to fabricate, thus realizes miniaturization of a tightly coupled array.
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表 1 优化参数值
Table 1. Optimized parameter value
(mm) dE dH w l W2 W3 W4 W5 l2 l3 l4 Wb 14.3 14.3 3.4 7.7 0.55 1.25 3 3 5 18 3.2 8 -
[1] Caminita F, Costanzo S, Massa G D, et al. Reduction of patch antenna coupling by using a compact EBG formed by shorted strips with interlocked branch-stubs[J]. IEEE Antennas and Wireless Propagation Letters, 2009, 8: 811-814. doi: 10.1109/LAWP.2009.2021589 [2] 唐明春, 肖绍球, 高山山, 等. 新型电谐振人工异向介质抑制阵列天线单元间互耦[J]. 物理学报, 2010, 59(3): 1851-1856. https://www.cnki.com.cn/Article/CJFDTOTAL-WLXB201003067.htmTang Mingchun, Xiao Shaoqiu, Gao Shanshan, et al. New type of electrical resonance artificial anisotropic medium suppresses mutual coupling between array antenna elements. Acta Physica Sinica, 2010, 59(3): 1851-1856 https://www.cnki.com.cn/Article/CJFDTOTAL-WLXB201003067.htm [3] Munk B, Pryor J, Durham T, et al. A low-profile broadband phased array antenna[C]//Antennas & Propagation Society International Symposium. 2003: 448-451. [4] Cedric W L, Dimitris P, Asimina K, et al. Body-worn 67: 1 bandwidth antenna using 3 overlapping dipole elements[C]//11th European Conference on Antennas and Propagation. 2017: 1557-1558. [5] Zhong J, Alwan E A, Volakis J L. Ultra-wideband dual-linear polarized phased array with 60° scanning for simultaneous transmit and receive systems[C]//International Workshop on Antenna Technology: Small Antennas, Innovative Structures, and Applications. 2017: 10-141. [6] Xiao Shiwei, Yang Shiwen, Chen Yikai, et al. An ultra-wideband tightly coupled dipole array co-designed with low scattering characteristics[J]. IEEE Transactions on Antennas and Propagation, 2019, 67(1): 676-680. doi: 10.1109/TAP.2018.2880038 [7] Doane J. Wideband low-profile antenna arrays: fundamental limits and practical implementations[J]. Dissertations & Theses-Gradworks, 2013, 76(5): 266. [8] Li Xue, Gu Changqing, Han Guodong, et al. A UWB wide-scan tightly coupled dipole array[C]//IEEE International Workshop on Electromagnetics: Applications and Student Innovation Competition. 2016: 1-3. [9] Yetisir E, Ghalichechian N, Volakis J L. Ultrawideband array with 70° scanning using FSS superstrate[J]. IEEE Transactions on Antennas and Propagation, 2016, 64(10): 4256-4265. doi: 10.1109/TAP.2016.2594817 [10] Kasemodel J A, Chen C C, Volakis J L. Wideband planar array with integrated feed and matching network for wide-angle scanning[J]. IEEE Transactions on Antennas and Propagation, 2013, 61(9): 4528-4537. doi: 10.1109/TAP.2013.2266090 [11] Zhou Wenyang, Chen Yikai, Yang Shiwen. Dual-polarized tightly coupled dipole array for UHF-X band satellite applications[J]. IEEE Antennas and Wireless Propagation Letters, 2016, 18(3): 467-471. [12] Novak M H, Volakis J L. Ultrawideband antennas for multiband satellite communications at UHF-Ku frequencies[J]. IEEE Transactions on Antennas and Propagation, 2015, 63(4): 1334-1341. doi: 10.1109/TAP.2015.2390616 [13] 陈常青, 周志鹏, 张金平, 等. 一种基于紧耦合结构的超宽带天线阵列设计[J]. 现代雷达, 2018, 40(2): 73-76. https://www.cnki.com.cn/Article/CJFDTOTAL-XDLD201802015.htmChen Changqing, Zhou Zhipeng, Zhang Jinping, et al. Design of ultra-wideband antenna array based on tightly coupled structure. Modern Radar, 2018, 40(2): 73-76 https://www.cnki.com.cn/Article/CJFDTOTAL-XDLD201802015.htm [14] Papantonis D, Volakis J. Dual polarized tightly coupled array with substrate loading[J]. IEEE Antennas & Wireless Propagation Letters, 2016, 15: 325-328. [15] Munk B A. Broadband wire arrays[M]. Finite Antenna Arrays and FSS, 2009. [16] Magill E, Wheeler H. Wide-angle impedance matching of a planar array antenna by a dielectric sheet[J]. IEEE Transactions on Antennas and Propagation, 1966, 14(1): 49-53. doi: 10.1109/TAP.1966.1138622 [17] Mailloux R J. Phased array antenna handbook[M]. 2nd Ed. Beijing: Publishing House of Electronics Industry, 2008.