An Ultra-Wideband Low-Profile Dipole Patch Antenna for VHF-Band Probing Radars

TIAN Yuxiao; ZHANG Feng; MA Zhangjun; WANG Jiacheng; JI Yicai

doi:10.11999/JEIT260105

Article Contents

Article Navigation > Journal of Electronics & Information Technology > 2025 >

TIAN Yuxiao, ZHANG Feng, MA Zhangjun, WANG Jiacheng, JI Yicai. An Ultra-Wideband Low-Profile Dipole Patch Antenna for VHF-Band Probing Radars[J]. Journal of Electronics & Information Technology. doi: 10.11999/JEIT260105

Citation:

TIAN Yuxiao, ZHANG Feng, MA Zhangjun, WANG Jiacheng, JI Yicai. An Ultra-Wideband Low-Profile Dipole Patch Antenna for VHF-Band Probing Radars[J]. Journal of Electronics & Information Technology. doi: 10.11999/JEIT260105

Citation:

PDF( 3135 KB)

An Ultra-Wideband Low-Profile Dipole Patch Antenna for VHF-Band Probing Radars

doi: 10.11999/JEIT260105 cstr: 32379.14.JEIT260105

TIAN Yuxiao^{1, 2},
ZHANG Feng^{1
,
,},
MA Zhangjun^{1, 2},
WANG Jiacheng^{1, 2},
JI Yicai¹

1.
Key Laboratory of Electromagnetic Radiation and Sensing Technology, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing 100190, China
2.
School of Electronic, Electrical, and Communication Engineering, University of Chinese Academy of Sciences, Beijing 101408, China

Funds: The National Key Research and Development Program of China(2024YFB3908003)

Received Date: 2026-01-28
Accepted Date: 2026-03-16
Rev Recd Date: 2026-03-10

Available Online: 2026-03-31

Abstract

Abstract

Objective In radar systems, the limitations of traditional narrowband antennas in data transmission rate and resolution have become increasingly evident. Ultra-WideBand (UWB) antennas therefore receive broad attention because they provide high range resolution and strong interference suppression capability. However, at low frequencies, existing UWB antennas usually suffer from excessively large physical size, which makes installation on airborne or vehicle-mounted platforms difficult. By contrast, compact antennas that are easier to deploy often exhibit insufficient gain and cannot satisfy the penetration-depth requirement of deep subsurface detection. Thus, achieving a proper balance among antenna size, bandwidth, and gain over an ultra-wideband range remains a major challenge for VHF-band probing radars. To address this issue, a planar dipole antenna loaded with an Artificial Magnetic Conductor (AMC) structure and metallic shorting walls is proposed. The antenna maintains stable radiation performance over a wide frequency range while preserving a low-profile and structurally simple configuration. Methods The reflection-phase characteristics of AMC unit cells with different geometries are compared, and square unit cells are selected to construct a 9 × 7 AMC reflective layer. Owing to its in-phase reflection property, the AMC structure removes the conventional requirement for a quarter-wavelength spacing between the antenna and a metallic ground plane, thereby reducing the profile height. The dipole patch adopts an optimized meandered current-bending structure to reduce the lateral size. Metallic shorting walls are further loaded at both ends of the antenna. According to image theory, equivalent currents are generated on the outer surfaces of these metal walls during operation, which effectively extends the electrical length and improves low-frequency performance without increasing the physical size. In addition, two vertical metallic walls are connected to the ground plane on both sides of the antenna to form a reflective back cavity, which strengthens unidirectional radiation and improves antenna gain. As part of the overall co-design, four 125 Ω resistors are inserted between the feed region and the metallic sidewalls. This resistive loading suppresses strong low-frequency resonances and broadens the impedance bandwidth at the cost of acceptable Ohmic loss. Results and Discussions A prototype with favorable simulated performance is fabricated and measured in a microwave anechoic chamber. The measured impedance bandwidth for VSWR<2 is 50～400 MHz, which agrees well with the simulated range of 84～366 MHz. The measured impedance matching is slightly better than the simulated result, mainly because cable loss and power-divider loss in the feeding network reduce the reflected power. The measured gain follows the same trend as the simulated gain, with deviations within 1 dBi. Radiation-pattern measurements show that at 100, 200, and 300 MHz, the measured copolarization patterns agree well with the simulated results, and the maximum radiation direction remains normal to the antenna plane, which confirms the effectiveness of the proposed design. As shown in Fig. 5, the current on the radiating patch layer mainly flows along the +x direction and generates a radiated electric field along the +z direction. The current on the AMC unit can be represented by an equivalent current loop oriented along the +z direction. At this frequency, the x-direction current and the parasitic current loop on the AMC jointly enhance the antenna gain. This result explains the gain-improvement mechanism of the AMC structure. When the operating frequency increases to 400 MHz, the electrical size of the antenna reaches approximately $ 1.6\lambda $, which causes main-lobe splitting and shifts the maximum radiation direction toward 90°. Although this high-frequency beam splitting introduces spatial clutter, it is an acceptable physical trade-off for achieving the ultra-low profile of 0.07 λ_L, while the overall UWB characteristic still supports high time-domain resolution in probing radar systems. At 400 MHz, the measured H-plane co-polarization level is slightly higher than the simulated value, possibly because of coupling between the feeding cable and the vertically mounted antenna. Conclusions A low-profile UWB planar dipole antenna is proposed for VHF-band probing radar applications. By combining the AMC layer, metallic shorting walls, and resistive loading, the proposed design improves impedance matching while preserving a compact size. The reflective back cavity further improves the realized gain. The fabricated prototype shows good agreement between measurement and simulation. The antenna operates over 100–366 MHz and exhibits a measured VSWR<2 bandwidth of 50～400 MHz. It maintains a compact electrical size of 0.38λ_L × 0.18λ_L × 0.07λ_L, and the maximum measured gain within the operating band reaches 6 dBi. The proposed co-design provides a practical solution for low-frequency probing radar antennas that require wide bandwidth, low profile, and relatively high gain.
- Artificial Magnetic Conductor (AMC),
- Low-profile,
- Ultra-WideBand (UWB),
- Gain enhancement

FullText(HTML)

References(27)

References

[1]	CHERAGHINIA M, SHAHID A, LUCHIE S, et al. A comprehensive overview on UWB radar: Applications, standards, signal processing techniques, datasets, radio chips, trends and future research directions[J]. IEEE Communications Surveys & Tutorials. 2025, 27(4): 2283–2324. doi: 10.1109/COMST.2024.3488173.
[2]	XIAO Jiang, ZHOU Zimu, YI Youwen, et al. A survey on wireless indoor localization from the device perspective[J]. ACM Computing Surveys (CSUR), 2017, 49(2): 25. doi: 10.1145/2933232.
[3]	TONG Jisheng, HUO Jianjian, LUO Jun, et al. A modified compact UWB directional bow-tie antenna for underwater GPR[J]. IEEE Antennas and Wireless Propagation Letters, 2025, 24(4): 943–947. doi: 10.1109/LAWP.2024.3522321.
[4]	GUPTA K, V A, ASOK A O, et al. Design of an ultra-wideband antipodal Vivaldi antenna for deep ground penetration and high-resolution through-wall imaging[C]. 2025 IEEE Space, Aerospace and Defence Conference (SPACE), Bangalore, India, 2025: 1–5. doi: 10.1109/SPACE65882.2025.11171106.
[5]	KADDOUR A S, BORIES S, BELLION A, et al. Frequency reconfigurable low-profile UWB magneto-electric dipole in VHF band[J]. IEEE Access, 2021, 9: 61269–61282. doi: 10.1109/ACCESS.2021.3073094.
[6]	HE Shuai, CHANG Lei, and CHEN Zhuangzhi. Design of a compact biconical antenna loaded with magnetic dipoles[J]. IEEE Antennas and Wireless Propagation Letters, 2017, 16: 840–843. doi: 10.1109/LAWP.2016.2608920.
[7]	TANABE M, MASUDA Y, and NAKANO H. Low-profile spiral antenna placed on an extremely thin magnetodielectric substrate[J]. IEEE Antennas and Wireless Propagation Letters, 2017, 16: 2050–2053. doi: 10.1109/LAWP.2017.2695488.
[8]	LI Donghao, DENG Changjiang, FU Zhewei, et al. Wideband electrically small vivaldi antenna using non-foster matching[J]. IEEE Antennas and Wireless Propagation Letters, 2025, 24(8): 2672–2676. doi: 10.1109/LAWP.2025.3571904.
[9]	JUNG T H, JUNG S C, RYU H K, et al. Ultrawideband planar dipole antenna with a modified taegeuk structure[J]. IEEE Antennas and Wireless Propagation Letters, 2015, 14: 194–197. doi: 10.1109/LAWP.2014.2359936.
[10]	BYERS K J, HARISH A R, SEGUIN S A, et al. A modified wideband dipole antenna for an airborne VHF ice-penetrating radar[J]. IEEE Transactions on Instrumentation and Measurement, 2012, 61(5): 1435–1444. doi: 10.1109/TIM.2011.2181780.
[11]	XIAO Ruqi, WEN Geyi, YANG Guo, et al. Application of resonant modal theory to the design of dual-band wideband dipole antenna[J]. IEEE Antennas and Wireless Propagation Letters, 2024, 23(8): 2551–2555. doi: 10.1109/LAWP.2024.3399405.
[12]	WANG H, PARK Y B, and PARK I. Ultrawideband mode-compressed dipole antenna with folded U-shaped reflector[J]. IEEE Transactions on Antennas and Propagation, 2025, 73(8): 6068–6073. doi: 10.1109/TAP.2025.3558609.
[13]	WANG Zihao, YE Shengbo, LU Wei, et al. A dual H-shaped ultrawideband antenna for AAV-based ground penetrating radar[J]. IEEE Antennas and Wireless Propagation Letters, 2025, 24(12): 4610–4614. doi: 10.1109/LAWP.2025.3606005.
[14]	SMITH L and LIM S. Design of a compact, planar, wideband, overlapped, bow-tie antenna in a single layer with stable bi-directional radiation patterns[J]. Applied Sciences, 2024, 14(20): 9555. doi: 10.3390/app14209555.
[15]	KIM W, LEE M S, SHIN G, et al. Ferrite-loaded, low-profile grounded bowtie-loop antenna for VHF communication[J]. IEEE Antennas and Wireless Propagation Letters, 2023, 22(12): 3132–3136. doi: 10.1109/LAWP.2023.3311965.
[16]	CHENG Hao, XIAO Gaobiao, and WANG Xiaocheng. A low-profile wideband patch antenna with modified parasitic mushroom structures on nonperiodic AMC[J]. IEEE Antennas and Wireless Propagation Letters, 2023, 22(4): 719–723. doi: 10.1109/LAWP.2022.3223156.
[17]	ZHOU Changfei, SUN Jiaxing, YANG Wenwen, et al. A wideband low-profile dual-polarized hybrid antenna using two different modes[J]. IEEE Antennas and Wireless Propagation Letters, 2023, 22(1): 114–118. doi: 10.1109/LAWP.2022.3204266.
[18]	SIEVENPIPER D, ZHANG Lijun, BROAS R F J, et al. High-impedance electromagnetic surfaces with a forbidden frequency band[J]. IEEE Transactions on Microwave Theory and Techniques, 1999, 47(11): 2059–2047. doi: 10.1109/22.798001.
[19]	WANG Zhendong, HUANG Shuai, LIU Jiangling, et al. A low profile wideband linearly polarized slot antenna using a circular AMC surface[C]. 2020 9th Asia-Pacific Conference on Antennas and Propagation (APCAP), Xiamen, China, 2020: 1–2. doi: 10.1109/APCAP50217.2020.9246108.
[20]	A. F. Berdasco, M. E. d. C. Gómez, J. Laviada, et al. AMC-Backed Twin Arrow Antenna for Wearable Electronic Travel Aid System at 24 GHz[J]. IEEE Antennas and Wireless Propagation Letters, 2024, 23(11):3337-3341. doi: 10.1109/LAWP.2024.3378012.
[21]	LI Yinuo and CHEN Juan. Design of miniaturized high gain bow-tie antenna[J]. IEEE Transactions on Antennas and Propagation, 2022, 70(1): 738–743. doi: 10.1109/TAP.2021.3098595.
[22]	JIANG Wen, DU Liang, GAO Yuchen, et al. A low-profile shared-aperture antenna using electromagnetic transparent structure and AMC[J]. IEEE Antennas and Wireless Propagation Letters, 2025, 24(10): 3619–3623. doi: 10.1109/LAWP.2025.3598326.
[23]	GIELIS J. A generic geometric transformation that unifies a wide range of natural and abstract shapes[J]. American Journal of Botany, 2003, 90(3): 333–338. doi: 10.3732/ajb.90.3.333.
[24]	ZHAI Huiqing, ZHANG Kedi, YANG Sen, et al. A low-profile dual-band dual-polarized antenna with an AMC surface for WLAN applications[J]. IEEE Antennas and Wireless Propagation Letters, 2017, 16: 2692–2695. doi: 10.1109/LAWP.2017.2741465.
[25]	V A G. Radiation characteristics of a low-profile UWB orthogonal polarizated slot radiator excited by printed dipole antennas[C]. 2020 IEEE Conference of Russian Young Researchers in Electrical and Electronic Engineering (EIConRus), St. Petersburg and Moscow, Russia, 2020: 1073–1075. doi: 10.1109/EIConRus49466.2020.9039111.
[26]	MAZZINGHI A, BARRAS D, DANEV B, et al. Miniaturized UWB dual-port antenna for localization applications[J]. IEEE Antennas and Wireless Propagation Letters, 2024, 23(3): 1080–1084. doi: 10.1109/LAWP.2023.3344593.
[27]	XU Lina, LI Li, and ZHANG Wenmei. Study and design of broadband bow-tie slot antenna fed with asymmetric CPW[J]. IEEE Transactions on Antennas and Propagation, 2015, 63(2): 760–765. doi: 10.1109/TAP.2014.2378265.