Military Antennas

Jae-Yoon Shin, Jong-Myung Woo Department of Radio Science and Engineering, Chungnam National University, Daejeon, Korea

Abstract - In this study, we designed antennas considering the military operational environments. First, a quad−band antenna that enabled multi-mode communication and could be mounted on the surface of a combat helmet was designed. The maximal gains of the designed antenna were −4.42 dBi in the VHF band for voice communication, 4.94 dBi in the disaster communication band, 2 dBi in the GPS L1 band, and 2.83 dBi in the WLAN band for image communication, and these were independent of directional constraints. In addition, a printed four-arrayed Yagi−Uda antenna, which works as a mono-pulse radar antenna mounted on a small missile surface, was also designed. This antenna has a director element, whose length is equal to one half of the operational wavelength, installed individually with the feeding point. This enables easy beam steering toward the direction of the missile. The antenna was arrayed in four directions with 90° separation between each array, and mounted on the warhead of the missile. The average maximal gains were 6.28 dBi in the E-plane, and 6.29 dBi in the H-plane, this confirmed that the antenna was suitable as a detector antenna mounted on a missile warhead.

Index Terms — Military antennas, Quad−band antenna, Printed Yagi-Uda antenna, Ultra-wide band antenna.

1. Introduction

Today, wireless technology accelerates the fusion of networking and intelligence technologies in both the industry and military. The military antenna market is projected to grow from an estimated USD 3.23 billion in 2017 to USD 4.30 billion by 2022, at a Compound Annual Growth Rate (CAGR) of 5.90% from 2017 to 2022. This is because the antennas must be designed considering the operating environment and the characteristics of the devices when carrying out military missions.

Therefore, considering military operation environments, we report our designed surface mounted quad-band antenna that enables multi-mode communication for combat helmets and a four-arrayed printed Yagi−Uda antenna that works as a seeker antenna mounted on the surface of a missile.

2. Surface-Mounted Quad-Band Antenna for Helmets

For the future battlefields, wireless devices that enable multi-mode communication, including the voice of an individual combat unit, image, and location information, is required. The existing antennas for military communication are monopole antennas that protrude externally. This could risk exposure to enemies, as well as cause discomfort during maneuvers and cover, and could thus be disadvantageous. Therefore, we designed a multi-band antenna to be mounted on the surface of a combat helmet.

Fig. 1. Structure of the proposed antenna

Fig.1 shows the structure of the surface-mounted quad-

band antenna for helmets. The antenna combines a printed folded monopole antenna and a reverse L parasitic element to compensate impedance for broadband matching [1], [2]. We than transformed the planar antenna into a helmet-mountable version with dimensions of 386 mm width and 87 mm length.

Fig. 2. Return loss of the proposed antenna

Fig.2 shows the return loss of the surface-mounted quad-

band antenna for the helmets. The -10 dB bandwidths were 8.1 MHz in VHF band (158 MHz) for voice communication, 560 MHz in the disaster communication band (700 MHz), 436 MHz in the GPS L1 band (1.575 GHz), and 812 MHz in the WLAN band (2.45 GHz) for image communication.

The radiation patterns of frequency bands are shown in Fig. 3. As the designed antenna includes reverse L element, there are horizontal and vertical transmission elements, for which. we confirmed radiation patterns. The maximal gains of the antenna were measured at -4.42 dBi (zx-plane) at 158 MHz, 4.94 dBi (zy-plane) at 700 MHz, 2 dBi (zx-plane) at 1.575 GHz, and 2.83 dBi (zy-plane) at 2.45 GHz. The patterns exhibit non-directionality at 158 MHz, despite a few generated nulls, the antenna transmitted in all directions at 700 MHz, 1.575 GHz, and 2.45 GHz.

2018 International Symposium on Antennas and Propagation (ISAP 2018)October 23~26, 2018 / Paradise Hotel Busan, Busan, Korea

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Fig. 3. Radiation patterns of the proposed antenna

Therefore, the designed antenna was confirmed to be

suitable as a multi-band system antenna mounted on the surface of a helmet.

3. Four-Array for Small Missile Warhead Using a Printed Monopole Yagi−Uda Antenna

To intercept long-range artillery, mortar, and rockets, missiles with high accuracy are required. Existing antennas that enhance interception accuracy have rather complicated structures and high manufacturing costs. Therefore, we designed a four-array printed Yagi−Uda antenna that could work as detector antenna mounted on a small missile surface at the designed frequency of 9.375 GHz to supplement the shortcomings of the existing antenna [3].

Fig. 4. Structure of the proposed antenna

Fig.4 shows the structure of the four-array printed

Yagi−Uda antenna. The conventional printed Yagi−Uda antenna needs modification of the ground to steer a beam toward the direction of the missile, which risks the abnormal operation of the director element. To overcome this, a director element of length equal to half the wavelength (λ/2) was designed to be installed individually with the feeding point, which makes it easy for beam steering toward the direction of the missile. Then, the antenna was arrayed in four ways with 90° separation between each array and mounted on the warhead of a missile.

Fig. 5. Radiation patterns of the proposed antenna.

The simulated, and measured radiation patterns of the

four-array printed Yagi−Uda antenna are shown in Fig. 5. The simulated and measured patterns had beam steering characteristics that could be aimed in the direction of the missile. The simulation showed maximal gains 6.24 dBi in both the E and H-planes, the measured maximal gains averaged at 6.28 dBi in the E-plane and 6.29 dBi in the H-plane.

Therefore, it was confirmed that the designed antenna was suitable as a detector antenna mounted on a missile warhead.

Several other military antennas were also designed, such as a broadband antenna to integrate all antennas used in a surveillance patrol UAV into one antenna [4].

4. Conclusion

In this paper, we presented two military antennas designed considering the military operational environment and the characteristics of devices when carrying out military missions.

First, a surface-mounted quad-band antenna for combat helmets was designed to enable multi-mode communication. The maximal gains of the designed non-directional antenna were -4.42 dBi in the VHF band for voice communication, 4.94 dBi in the disaster communication band, 2 dBi in the GPS L1 band, and 2.83 dBi in the WLAN band for image communication.

Second, the four-array printed Yagi−Uda antenna was designed to work as a detector antenna mounted on the surface of a small missile. The designed antenna has director element of λ/2 length, installed individually with the feeding point, which makes it easy for beam steering toward the direction of the missile. The antenna was arrayed in four ways with 90° separation between each array and mounted on the warhead of a missile. The average maximum gain was confirmed to be 6.28 dBi in the E-plane and 6.29 dBi in the H-plane.

References

[1] K.-B. Kim, H.-K. Ryu, J.-M. Woo, “Compact wideband folded monopole antenna coupled with parasitic inverted-L element for laptop computer applications,” Electronics Lett., vol. 47, pp. 301-303, 2011.

[2] Jae-Min Keum, Seung-Min Kim, Jun-Won Kim, Seo-Cheol Jung, Jung -Myung Woo, “Surface Mounted Quad-band Antenna for Helmets,” in Proc. The Korea Institute of Intelligent Transport Systems (ITS) Conf., 2015, Jeju, Korea, pp. 106.

[3] Jae-Yeop Jeong, Jong-Myung Woo, “Design of a printed Antenna for a small passive microwave applications,” in Proc. International Military Science and Technology Fair, 2016, Seoul, Korea, pp. 90.

[4] Jae-Yeop Jeong, Jong-Myung Woo, “Ultra-wide band antenna attachable on UAV surface,” Int J RF Microw Comput Aided Eng., vol. 27, 2017.

2018 International Symposium on Antennas and Propagation (ISAP 2018)October 23~26, 2018 / Paradise Hotel Busan, Busan, Korea

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