Omnidirectional Circularly Polarized Antenna Based on Counter-Wound Helices

Hu, Zhenxin; Lin, Wei; Chen, Zhuozhu; Wang, Wenwei; Wang, Shiyan; Li, Jianfeng; Al-Sheikh, Ali

doi:10.1109/tap.2021.3061011

Cited by 14 publications

(15 citation statements)

References 23 publications

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“…Thus, it is relatively easy to achieve circular polarization in a structure such as the λ /2 helix shown in Figure 3A. However, the problem is that its input resistance near the resonant frequency, f 0 , is very small due to the small antenna volume in Reference [19], rendering it less attractive for use as an OCP antenna or an array element. One viable way to obtain a larger resistance is to increase the antenna size.…”

Section: Operation Principlementioning

confidence: 99%

“…In case S 1 and S 2 are equal, the condition of circular polarization can be easily derived, following Reference [20], as

\frac{s_{1}}{λ} goodbreak= {(\frac{πD}{\sqrt{2} λ})}^{2}

In case S 1 and S 2 are not identical, circular polarization can still be achieved when the total vertical and horizontal components of far‐zone electric fields are equal. Following Reference [19], the CP condition can be approximately formulated as

\frac{n_{1} s_{1} + 2 n_{2} s_{2}}{λ} goodbreak= ((), n_{1} goodbreak+ 2 n_{2}) \cdot {(\frac{πD}{\sqrt{2} λ})}^{2}

Note that the thickness of helical wires and edge effect are not considered in Equation (). It is meant to estimate the initial values of the antenna parameters.…”

Section: Operation Principlementioning

confidence: 99%

“…In case S 1 and S 2 are not identical, circular polarization can still be achieved when the total vertical and horizontal components of far-zone electric fields are equal. Following Reference [19], the CP condition can be approximately formulated as…”

Section: Operation Principlementioning

confidence: 99%

“…Similarly in Reference [18], a normal mode helix with coupling feed structure can provide a good impedance bandwidth, while the gain of all designs is less than 2 dBic. Whereas in Reference [19], an innovative counter‐wound helical antenna was proposed, achieving an OCP beam with a simple and neat configuration.…”

Section: Introductionmentioning

confidence: 99%

“…The OCP beams realized in the abovementioned designs usually feature a large size or complex feeding and matching networks. Specifically, the designs based on the normalmode helical structure, such as the works in References [17][18][19]. They enable the CP feature of the normal-mode helix while only solving the matching issue.…”

Section: Introductionmentioning

confidence: 99%

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Omnidirectional circularly polarized collinear helical antenna using self‐canceling sections

Al-Sheikh³

et al. 2022

Int J RF Mic Comp-Aid Eng

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An omnidirectional circularly polarized (OCP) collinear helical antenna employing a form of self-canceling sections is proposed in this paper. It consists of three separateλ/2 (where λis the free space wavelength at the center frequency) helical sections, which serve as the radiating elements, and two λ/2 self-canceling sections to connect them. The self-canceling section is simply a wire folded in half to form two parallel sections with surface current directions opposing each other, thereby canceling out the far-field components. The current direction is reversed every half wavelength at the operating frequency. Thus, the surface current vector along the three helical wires would point in the same direction, achieving enhanced radiation.A prototype of the proposed antenna with a diameter of 0.12λand a height of 0.51λhas been fabricated and tested. Measured results demonstrate a maximum gain of 2.23 dBic, an axial ratio and impedance bandwidth of 15.8% and 2%, respectively.

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Section: Operation Principlementioning

confidence: 99%

“…In case S 1 and S 2 are equal, the condition of circular polarization can be easily derived, following Reference [20], as

\frac{s_{1}}{λ} goodbreak= {(\frac{πD}{\sqrt{2} λ})}^{2}

\frac{n_{1} s_{1} + 2 n_{2} s_{2}}{λ} goodbreak= ((), n_{1} goodbreak+ 2 n_{2}) \cdot {(\frac{πD}{\sqrt{2} λ})}^{2}

Note that the thickness of helical wires and edge effect are not considered in Equation (). It is meant to estimate the initial values of the antenna parameters.…”

Section: Operation Principlementioning

confidence: 99%

Section: Operation Principlementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Omnidirectional circularly polarized collinear helical antenna using self‐canceling sections

Al-Sheikh³

et al. 2022

Int J RF Mic Comp-Aid Eng

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Investigation on a compact wideband omnidirectional circularly polarized antenna in an indoor propagation channel for 2.4 GHz application

Emadian,

Ghobadi

2024

Int J Communication

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SummaryIn this paper, for the first time, the capability of a compact low‐cost wideband omnidirectional circularly polarized (CP) antenna to suppress multipath fading characteristics in a typical indoor propagation channel for 2.4 GHz applications is investigated. A ray tracing method based on the geometrical optics and uniform theory of diffraction is applied to analyze an indoor propagation channel using the measured radiation patterns of the proposed antenna. The design uses a conventional monopole antenna with a circular ground plane to generate a vertically polarized electric field. Sequentially flag‐shaped stubs are then added to the ground plane to produce horizontally polarized electric field and to improve the impedance bandwidth of the proposed antenna. The antenna is designed for 2.4 GHz WLAN application with 10 dB impedance bandwidth of 25.5% and 3 dB axial ratio (AR) bandwidth of 24.5%. The polarization can be readily changed between the left‐hand circular polarization (LHCP) and right‐hand circular polarization (RHCP) by altering the direction of the coaxial probe (monopole) or varying the orientation of the printed bended stubs. Both the LHCP and RHCP prototypes of the proposed antenna are designed, fabricated, and tested, and the similar results are obtained.

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Circularly polarized Yagi array with small size and symmetric pattern by using counter‐wound helix

Huang

Chen

et al. 2022

Int J RF Mic Comp-Aid Eng

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A circularly polarized Yagi array with a compact structure, small size, and symmetric pattern is reported in this paper. It consists of four 3-segment counter-wound helices, one driven element, one director, and two reflectors, for a moderate gain and front-to-back ratio. Similar to conventional Yagi with linear polarization, all helical elements have different but close resonant frequencies. The driven element has a resonant frequency higher than that of the reflectors but lower than that of the director. Owing to the uniform pattern of the counter-wound helical element, a very symmetric pattern with circular polarization at the endfire direction is achieved. A prototype of the 4-element array is fabricated and tested. Measured results show that an impedance bandwidth with jS 11 j < À10 dB from 1.345 to 1.42 GHz (5.42%) and a 3-dB AR band from 1.34 to 1.43 GHz (6.5%) are obtained, showing an overlapped bandwidth of 5.42%. A realized gain up to 7.03 dBi and an offset angle within 3 are also realized. The overall size of the array is as small as 0.66λ 0 Â 0.107λ 0 Â 0.40λ 0 , showing possibility of further being formed to large scanning or multi-beam arrays.

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Omnidirectional Circularly Polarized Antenna Based on Counter-Wound Helices

Cited by 14 publications

References 23 publications

Omnidirectional circularly polarized collinear helical antenna using self‐canceling sections

Omnidirectional circularly polarized collinear helical antenna using self‐canceling sections

Investigation on a compact wideband omnidirectional circularly polarized antenna in an indoor propagation channel for 2.4 GHz application

Circularly polarized Yagi array with small size and symmetric pattern by using counter‐wound helix

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