A Ku-Band Circularly Polarized Leaky-Wave Antenna Loaded with Parasitic Slots
-
摘要: 该 文提出一种基于基片集成波导(SIW)的加载与辐射缝隙结构相同但尺寸缩小的寄生结构以克服开阻带问题同时改善阻抗匹配性能的Ku波段圆极化漏波天线设计方法。所设计的辐射缝隙能够有效激励圆极化波，而寄生缝隙则可在抑制开阻带效应的同时，展宽整体辐射的圆极化带宽。对加工的原型天线进行测试的结果表明，该天线在12.6～17.4 GHz频段内具有32%的3 dB轴比带宽，同时实现了-49°～14°的圆极化波束扫描，并且在频段内的增益保持稳定。与现有相近工作相比，扫描角度范围达到了最大。Abstract:
This paper proposes a Ku-band circularly polarized Leaky-Wave Antenna (LWA) based on a Substrate Integrated Waveguide (SIW). A parasitic slot, with the same configuration as the main radiation slot but reduced in size, is employed to address the open-stopband problem and enhance impedance matching. The radiation slot excites Circularly Polarized (CP) waves, while the parasitic slot simultaneously broadens the Axial Ratio (AR) bandwidth and suppresses the open-stopband effect. A prototype antenna is designed, fabricated, and measured. The results demonstrate that the antenna achieves a 32% 3-dB AR bandwidth from 12.6 GHz to 17.4 GHz, with CP beam scanning from −49° to +14°. The simulated and measured results are in good agreement. In addition, the realized gain remains stable across the operating band. Compared with existing works, the proposed design achieves the widest scanning range. Objective Compared with traditional phased array antennas, frequency-scanning antennas have extensive applications in both military and civilian fields owing to their advantages of low profile, low cost, and lightweight design. CP waves offer superior anti-interference performance compared with linearly polarized waves. As a representative frequency-scanning antenna, the LWA has attracted sustained global research interest. This study focuses on the investigation of a Ku-band Circularly Polarized Leaky-Wave Antenna (CP-LWA), with emphasis on wide-bandwidth and wide-scanning techniques, as well as methods for achieving circular polarization. The aim is to provide potential design concepts for next-generation mobile communication and radar system antennas. Methods The fan-shaped slot is modified based on previous work, and an additional size-reduced parasitic slot of the same shape as the main slot is introduced. The parasitic slots cancel the reflected waves generated by the main radiating slot, thereby suppressing the Open-Stop-Band (OSB) effect, and they also enlarge the effective radiating aperture, which improves radiation efficiency and impedance matching. By exploiting the metallic boundary of the conductors, the parasitic slots enhance CP performance and broaden the AR bandwidth. To validate the proposed design, an antenna consisting of 12 main slots and 11 parasitic slots is designed, simulated, and measured. Results and Discussions A prototype is designed, fabricated, and measured in a microwave anechoic chamber to validate the proposed antenna. Both simulated and measured S11 values remain below −10 dB across the entire Ku-band. The measured S11 is slightly higher in the low-frequency range (12–13 GHz) and slightly lower in the high-frequency range (16–18 GHz), while maintaining an overall consistent trend with the simulations, except for a frequency shift of approximately 0.2 GHz toward lower frequencies. For the AR bandwidth, the simulated and measured 3-dB AR bandwidths are 32.7% (12.8–17.8 GHz) and 32.0% (12.6–17.4 GHz), respectively. The realized gains are on average 0.6 dB lower than the simulated values across the AR bandwidth, likely due to measurement system errors and fabrication tolerances. The simulated and measured peak gains reach 14.26 dB and 13.65 dB, respectively, with maximum gain variations of 2.91 dB and 2.85 dB. The measured AR and gain results therefore show strong agreement with the simulations. The measured sidelobe level increases on average by approximately 0.85 dB. The simulated CP scanning range extends from −47° to +17°, while the measured range narrows slightly to −49° to +14°. The frequency shift of the LWA is analyzed, and based on the simulated effect of variations in εr on the scanning patterns, the shift toward lower frequencies is attributed to the actual dielectric constant of the substrate being smaller than the nominal value of 2.2 specified by the manufacturer. Conclusions This paper proposes a Ku-band CP-LWA based on a SIW. The antenna employs etched slots consisting of fan-shaped radiation slots and size-reduced parasitic slots. The radiation slots excite circular polarization due to their inherent geometric properties, while the parasitic slots suppress the CP effect and broaden the CP bandwidth. Measurements confirm that the proposed LWA achieves a wide 3-dB AR bandwidth of 12.6–17.4 GHz (32%) with a CP beam scanning range from −49° to +14°. Meanwhile, the antenna demonstrates stable gain performance across the entire AR bandwidth. -
表 1 本文工作与近几年参考文献的对比
文献 天线类型 3 dB轴比带宽(GHz) 圆极化扫描范围(°) 最大增益差值(dB) [11] SIW+
T形缝隙12～18 (40%) –13～28 2.42 [15] SIW+
阿基米德螺旋形缝隙27.7～34.6 (22%) –51～–10 2.35 [16] SIW+
扇形缝隙27.4～37.3 (31%) –51～0 5.50 [18] 微带+
三角形贴片21.4～29 (30.5%) –19～22 ≈ 4.00 [19] 微带+梳状线 9.55～9.95 (4%) –12～10 0.50 本文工作 SIW+
扇形缝隙+寄生缝隙12.6～17.4 (32%) –49～14 2.85 
下载: 导出CSV
-
[1] JACKSON D R, CALOZ C, and ITOH T. Leaky-wave antennas[J]. Proceedings of the IEEE, 2012, 100(7): 2194–2206. doi: 10.1109/JPROC.2012.2187410. [2] SAJEEV K F, RAMAN S, and GOPIKRISHNA M. A frequency-agile and wide-scanning CRLH leaky-wave antenna for advanced wireless systems[J]. IEEE Antennas and Wireless Propagation Letters, 2025, 24(6): 1532–1536. doi: 10.1109/LAWP.2025.3542297. [3] LIU Shan, LI Zheng, CHEN Meie, et al. A 2-D circularly polarized fixed-frequency beam-scanning leakywave antenna for millimeter-wave satellite communications[J]. IEEE Transactions on Antennas and Propagation, 2024, 72(8): 6530–6540. doi: 10.1109/TAP.2024.3424589. [4] OTTO S, CHEN Zhichao, AL-BASSAM A, et al. Circular polarization of periodic leaky-wave antennas with axial asymmetry: Theoretical proof and experimental demonstration[J]. IEEE Transactions on Antennas and Propagation, 2014, 62(4): 1817–1829. doi: 10.1109/TAP.2013.2297169. [5] AHMAD A and MUKHERJEE J. Microstrip leaky-wave antenna with circular polarization and broadside radiation[J]. IEEE Antennas and Wireless Propagation Letters, 2023, 22(9): 2265–2269. doi: 10.1109/LAWP.2023.3283398. [6] HALL P S. Microstrip linear array for polarisation-agile antenna applications[C]. Proceedings of 1981 11th European Microwave Conference, Amsterdam, Netherlands, 1981: 813–818. doi: 10.1109/EUMA.1981.333038. [7] SACCO G, CAYTAN O, PISA S, et al. Analysis and modelling of rampart line antennas[J]. IET Microwaves, Antennas & Propagation, 2021, 15(12): 1605–1617. doi: 10.1049/mia2.12168. [8] ZHAO Shengnan and DONG Yuandan. Communication compact microstrip leaky-wave antenna for wide-angle beam scanning with circular polarization[J]. IEEE Transactions on Antennas and Propagation, 2022, 70(12): 12288–12293. doi: 10.1109/TAP.2022.3209187. [9] GETSINGER W. Elliptically polarized leaky-wave array[J]. IRE Transactions on Antennas and Propagation, 1962, 10(2): 165–171. doi: 10.1109/TAP.1962.1137830. [10] LIU Juhua, TANG Xihui, LI Yuanxin, et al. Substrate integrated waveguide leaky-wave antenna with H-shaped slots[J]. IEEE Transactions on Antennas and Propagation, 2012, 60(8): 3962–3967. doi: 10.1109/TAP.2012.2201085. [11] HONG Rentang, SHI Jiaqi, GUAN Dongfang, et al. Wideband and low-loss beam-scanning circularly polarized antenna based on air-filled SIW[J]. IEEE Antennas and Wireless Propagation Letters, 2021, 20(7): 1254–1258. doi: 10.1109/LAWP.2021.3077263. [12] LYU Yuelong, MENG Fanyi, YANG Guohui, et al. Periodic SIW leaky-wave antenna with large circularly polarized beam scanning range[J]. IEEE Antennas and Wireless Propagation Letters, 2017, 16: 2493–2496. doi: 10.1109/LAWP.2017.2726089. [13] CHEN Shulin, KARMOKAR D K, LI Zheng, et al. Circular-polarized substrate-integrated-waveguide leaky-wave antenna with wide-angle and consistent-gain continuous beam scanning[J]. IEEE Transactions on Antennas and Propagation, 2019, 67(7): 4418–4428. doi: 10.1109/TAP.2019.2911398. [14] LU Jingzheng, GENG Junping, WANG Kun, et al. A wideband circularly polarized periodic leaky-wave antenna using a novel unit cell with X-shaped slot[J]. IEEE Transactions on Antennas and Propagation, 2023, 71(8): 6639–6651. doi: 10.1109/TAP.2023.3284001. [15] LI Xiaowen, WANG Junhong, LI Zheng, et al. Circularly polarized leaky-wave antenna with natural curl property[J]. IEEE Antennas and Wireless Propagation Letters, 2022, 21(3): 466–470. doi: 10.1109/LAWP.2021.3135840. [16] LI Xiaowen, WANG Junhong, GOUSSETIS G, et al. Circularly polarized high gain leaky-wave antenna for CubeSat communication[J]. IEEE Transactions on Antennas and Propagation, 2022, 70(9): 7612–7624. doi: 10.1109/TAP.2022.3167773. [17] LIU Juhua, ZHOU Wenlong, and LONG Yunliang. A simple technique for open-stopband suppression in periodic leaky-wave antennas using two nonidentical elements per unit cell[J]. IEEE Transactions on Antennas and Propagation, 2018, 66(6): 2741–2751. doi: 10.1109/TAP.2018.2819701. [18] DU Wen, ZHANG Chaoqun, and ZHANG Jun. Circularly polarized leaky-wave antennas based on periodically arranged rotated right-angle triangular microstrip patches[J]. IEEE Transactions on Antennas and Propagation, 2023, 71(5): 4085–4093. doi: 10.1109/TAP.2023.3249120. [19] OGURTSOV S and KOZIEL S. A conformal circularly polarized series-fed microstrip antenna array design[J]. IEEE Transactions on Antennas and Propagation, 2020, 68(2): 873–881. doi: 10.1109/TAP.2019.2943326. -
图(19) / 表(1)
计量
- 文章访问数: 21
- HTML全文浏览量: 8
- PDF下载量: 0
- 被引次数: 0
下载:
