Generation of OAM Beams Using Phased Array in the Microwave Band

Liu, Kang; Liu, Hongyan; Qin, Yuliang; Cheng, Yongqiang; Wang, Shunan; Li, Xiang; Wang, Hongqiang

doi:10.1109/tap.2016.2589960

Cited by 201 publications

(92 citation statements)

References 19 publications

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“…Since the year of 2007, the OAM has been applied in the radio domain, which might offer a solution to the problem of radio-band congestion [1], [3], [4]. However, OAM multiplexing in the wireless communication has also caused controversy [5]. For radar detection and imaging realms, the helical phase-front can be exploited to improve the resolution of the cross-range profile of the target [6]- [8].…”

Section: Introductionmentioning

confidence: 99%

Sidelobe Suppression and Beam Collimation in the Generation of Vortex Electromagnetic Waves for Radar Imaging

Qin

Liu

Cheng

et al. 2017

Antennas Wirel. Propag. Lett.

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For the electromagnetic (EM) vortex imaging purposes, the side-lobe suppression and the beam collimation method in the generation of OAM-beams is proposed. Based on the concentric-ring array, the objective function for the generic algorithm (GA) is defined to calculate the signal amplitude for each ring. Comprehensive simulations are conducted to validate the effectiveness of the proposed method. Results show that the main lobes of the radiation pattern of different OAM modes are collimated in the same direction and the side lobes are all lower than -20 dB. Furthermore, the imaging model of the concentric-ring array is established and the target image is obtained through numerical simulations. The work can advance the development of the EM vortex imaging technique and novel radar detection technology as well.

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Section: Introductionmentioning

confidence: 99%

Sidelobe Suppression and Beam Collimation in the Generation of Vortex Electromagnetic Waves for Radar Imaging

Qin

Liu

Cheng

et al. 2017

Antennas Wirel. Propag. Lett.

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“…In the microwave and millimeter-wave bands, 6 when the traditional electromagnetic (EM) wave is modulated with OAM, a helical wavefront shape occurs, referred to as "vortex electromagnetic wave". Hitherto, the research of OAM and vortex EM waves has mainly focused on the generation of OAM beams, including OAM antenna design, 7 the phased array approach 8 and metasurface, [9][10][11] OAM-based wireless communications, 12,13 and OAM-based radar target detection and imaging. 6,14 With additional rotational degrees of freedom generated by OAM and the helical wavefront distribution, OAM-based radar has several distinguished merits, e.g., rotational frequency shift can be enhanced and detected without radial translation between radar and target, 15 the azimuthal information of targets can be estimated without any relative moves or beam scanning as traditional methods required, 6 the OAM-based radar can make a breakthrough on the Raleigh limit and achieve superresolution for target imaging.…”

Section: Introductionmentioning

confidence: 99%

Target scattering characteristics for OAM-based radar

Liu

Gao

et al. 2018

AIP Advances

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The target scattering characteristics are crucial for radar systems. However, there is very little study conducted for the recently developed orbital angular momentum (OAM) based radar system. To illustrate the role of OAM-based radar cross section (ORCS), conventional radar equation is modified by taking characteristics of the OAM waves into account. Subsequently, the ORCS is defined in analogy to classical radar cross section (RCS). The unique features of the incident OAM-carrying field are analyzed. The scattered field is derived, and the analytical expressions of ORCSs for metal plate and cylinder targets are obtained. Furthermore, the ORCS and RCS are compared to illustrate the influences of OAM mode number, target size and signal frequency on the ORCS. Analytical studies demonstrate that the mirror-reflection phenomenon disappears and peak values of ORCS are in the non-specular direction. Finally, the ORCS features are summarized to show its advantages in radar target detection. This work can provide theoretical guidance to the design of OAM-based radar as well as the target detection and identification applications.

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“…Moreover, in the area of microwave wireless communications, OAM modes are considered potential candidates for increasing capacity without requiring any extra frequency resources. The ith element is driven by a signal with a l i  phase delay, where 2 / , l l N    |l| is an integer smaller than N/2 [13], [14]. The key technologies of OAM-mode-based communications are associated with the mode generation and multiplexing steps.…”

Section: Introductionmentioning

confidence: 99%

“…A UCA is an array of N sub-antennas located along a circumference at equal spacing. The ith element is driven by a signal with a l i  phase delay, where 2 / , l l N    |l| is an integer smaller than N/2 [13], [14]. In these conditions, the wave front will contain the desired jl e  phase factor.…”

Section: Introductionmentioning

confidence: 99%

Microwave Orbital Angular Momentum Mode Generation and Multiplexing Using a Waveguide Butler Matrix

Lee¹,

Hong²,

Kang³

et al. 2017

ETRI Journal

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In this paper, we propose a convenient microwave orbital angular momentum (OAM) mode generation and multiplexing method operating in the 18 GHz frequency band, based on a 2×2 uniform circular array and a 4×4 Butler matrix. The three OAM modes −1, 0, and +1 were generated and verified using spatial S‐parameter measurements; the measured back‐to‐back mode isolation was greater than 17 dB in the full 17 GHz to 19 GHz range. However, the radiated OAM beam centers were slightly dislocated and varied with both frequency and the mode index, because of the non‐ideal characteristics of the Butler matrix. This resulted in mode isolation degradation and transmission distance limitations.

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Generation of OAM Beams Using Phased Array in the Microwave Band

Cited by 201 publications

References 19 publications

Sidelobe Suppression and Beam Collimation in the Generation of Vortex Electromagnetic Waves for Radar Imaging

Sidelobe Suppression and Beam Collimation in the Generation of Vortex Electromagnetic Waves for Radar Imaging

Target scattering characteristics for OAM-based radar

Microwave Orbital Angular Momentum Mode Generation and Multiplexing Using a Waveguide Butler Matrix

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