摘要 :
Next-generation wireless communication requires antennas with excellent performance and low-profile structures. A low-profile broadband dual-polarized base station antenna array with an artificial magnetic conductor (AMC) reflecto...
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Next-generation wireless communication requires antennas with excellent performance and low-profile structures. A low-profile broadband dual-polarized base station antenna array with an artificial magnetic conductor (AMC) reflector and cross-polarization suppression structures is proposed. Cross-polarization is effectively suppressed by introducing the structures among the antenna elements with almost no impact on the other antenna performances, and the cross-polarization suppression mechanism is analyzed theoretically. The AMC reflector reduces the antenna profile only
$0.12\lambda _{0}$
(
$\lambda _{0}$
is the free-space wavelength at 4 GHz). Prototypes of the antenna element and the five-element antenna array are fabricated, and the simulated and measured results indicate that both achieve good performance over the entire operating frequency band. The antenna array has high isolation (>28 dB), a wide operating bandwidth (3.14–5.32 GHz, 51.5%), and stable radiation performances (XPD >29 dB, gain >15 dBi, FBR >37 dB). The proposed antenna array with good performance and a low profile may be a candidate for 5G communication applications.
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摘要 :
An all-textile broadband circularly polarized (CP) antenna assisted by a nonuniform metasurface (MS) is proposed for 5.8 GHz wireless body area networks. The proposed antenna is comprised of a driven radiator of slot antenna and a...
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An all-textile broadband circularly polarized (CP) antenna assisted by a nonuniform metasurface (MS) is proposed for 5.8 GHz wireless body area networks. The proposed antenna is comprised of a driven radiator of slot antenna and a broadband CP converter of nonuniform MS with 3 × 3 unit-cells. The slot antenna with a hexagonal shape was initially designed for narrow band and linear polarization. A nonuniform MS with a central-notched hexagonal shape is placed on top of the slot antenna, which produces the broadband CP; the MS unit-cell is designed first to convert the incident wave to an orthogonal direction over a broad band and, second, to excite the resonant modes adjacent to the slot antenna mode, resulting in a broad band. Third, because of the proposed nonuniform MS configuration, the smaller unit-cell excites the resonant mode at higher frequency compared to the larger unit-cell at the center, enhancing operating bandwidth compared to the uniform MS. The proposed antenna is measured in free-space and on phantom-head environments to qualify the antenna for wearable applications. The specific absorption rate is also evaluated for safety usage and satisfies US and EU standards.
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In this letter, a hybrid wideband decoupling method based on far-field radiation regulation by employing the specially engineered periodic near-field resonators, which consist of split-ring resonator (SRR) arrays, is presented for...
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In this letter, a hybrid wideband decoupling method based on far-field radiation regulation by employing the specially engineered periodic near-field resonators, which consist of split-ring resonator (SRR) arrays, is presented for the two collinear transceiving horn antennas with extremely large element spacing. Two E-plane-coupled antennas operating at X-band are arranged with center-to-center distance of 8 m (over 200λ). By allocating the SRR arrays in close proximity to each horn antenna, the radiation power in the specified horizontal directions pointing to each other could be significantly reduced without disturbing their radiation characteristics in the broadside thus leading to the conspicuous port isolation enhancement. It is validated that more than 25 dB mutual coupling level reduction is achieved over the frequency range of 8–11.5 GHz (∼35.9% fractional bandwidth) when the SRR arrays are integrated. Finally, a prototype was fabricated and measured. Corresponding measurement results are in good agreement with the simulated ones.
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A millimeter-wave (mm-wave) dual-polarization bidirectional multibeam array antenna based on substrate integrated waveguide (SIW) technology is presented in this article, which can generate 16 bidirectional radiation beams with tw...
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A millimeter-wave (mm-wave) dual-polarization bidirectional multibeam array antenna based on substrate integrated waveguide (SIW) technology is presented in this article, which can generate 16 bidirectional radiation beams with two orthogonal linear polarizations. The proposed dual-polarization bidirectional multibeam array antenna, based on a new configuration, consists of two transverse slot array antennas (TSAAs), two longitudinal slot array antennas (LSAAs), and two dual-layer
$8 \times 8$
Butler matrices (BMs). To realize dual polarizations, a new type of TSAA is designed and combined with a conventional LSAA. For the purpose of bidirectional radiation, two types of dual-polarization array antenna (DPAA), which are realized by combining different arrangements of the TSAA and the LSAA, is composited. In addition, a dual-layer
$8 \times 8$
BM is developed, which can excite both the TSAA and the LSAA and generate dual-polarization bidirectional multibeam. Finally, the prototype of the planar dual-polarization bidirectional multibeam array antenna is fabricated, measured, and discussed. The measured results satisfactorily validate the simulated results.
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摘要 :
A novel, three-in-one antenna system suitable for WLAN operation in the 5 GHz band is presented. The design is based upon incorporating one slot and two dipole antennas into a compact multiantenna system that has comparable dimens...
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A novel, three-in-one antenna system suitable for WLAN operation in the 5 GHz band is presented. The design is based upon incorporating one slot and two dipole antennas into a compact multiantenna system that has comparable dimensions of a single mobile-unit antenna element. The three antennas are arranged parallel to each other with the two dipoles set on the right and left sides of the slot respectively. With this arrangement, not only can compact integration of three individual antennas be realized, pattern diversity and polarization diversity are also obtained. A design prototype has been constructed and tested. The results show that the coupling or the antenna port isolation is below -20 dB and good radiation characteristics have been observed.
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摘要 :
A low-scattering dipole antenna by loading mushroom-shaped electromagnetic structures is proposed and employed to design an aperture-shared antenna array with low blockage effect. The arm of the proposed dipole element consists of...
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A low-scattering dipole antenna by loading mushroom-shaped electromagnetic structures is proposed and employed to design an aperture-shared antenna array with low blockage effect. The arm of the proposed dipole element consists of a square ring and a short branch, and the mushroom structure is loaded on the arm to realize low scattering characteristics. The low scattering low band (LB) element is used for a dual-band shared-aperture array; the results indicate the pattern distortion of the high band (HB) array caused by the LB element can be greatly reduced accordingly. Compared with HB antenna alone, the simulated maximum gain decrease is 1.55 dB and the maximum beamwidth deviation is 27.4° after adding the reference LB dipole without loading the mushroom-shaped structure. Meanwhile the two values are reduced to 0.55 dB and 6.4°, respectively, after the mushroom-shaped structure is loaded. For demonstration, an aperture-shared antenna array operating in the LB of 0.698–0.96 GHz and the HB of 3.4–3.8 GHz is designed and fabricated. The measured results show that the S -parameters and the pattern of the HB subarray with the proposed LB dipole change slightly, indicating that the proposed LB dipole can effectively suppress the scattering on the HB antenna. The results indicate the proposed design is suitable for multiband aperture-shared antennas in modern communication systems.
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摘要 :
In this letter, a compact metasurface antenna array with diverse polarizations is proposed. The array element is a dual-polarized metasurface antenna driven with a square patch. In order to have compact size and low sidelobes for ...
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In this letter, a compact metasurface antenna array with diverse polarizations is proposed. The array element is a dual-polarized metasurface antenna driven with a square patch. In order to have compact size and low sidelobes for the antenna array, shared radiating elements are applied for both polarizations with a size reduction of 18.8% for a 1 × 4 antenna array. The diverse polarization property is achieved with the method of maximum power transmission efficiency (MMPTE), in which a dual-feed patch antenna connected to an ideal power combiner is chosen as the receiving antenna. With different scattering matrices of the power combiner, it is easy to calculate the excitation distribution for any polarizations with maximum gain. For demonstration, the antenna array with diverse polarizations is designed, fabricated, and measured.
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A novel broadband low-profile circularly polarized (CP) magneto-electric (ME) dipole antenna is proposed in the letter. Sharing the same aperture, a pair of electric dipoles (E-dipoles) and a pair of magnetic dipoles (M-dipoles) a...
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A novel broadband low-profile circularly polarized (CP) magneto-electric (ME) dipole antenna is proposed in the letter. Sharing the same aperture, a pair of electric dipoles (E-dipoles) and a pair of magnetic dipoles (M-dipoles) are combined through four bulges in the corners of the ring. The arms of the ring work as dipole antennas, i.e., E-dipoles, whereas the slots formed by the ring with bulges and the central patch work as slot antennas, i.e., M-dipoles. To realize CP radiation, a pair of vacant-quarter printed rings with short-end microstrip lines is utilized to excite the dipole and slot antennas simultaneously. The measurement results indicate that a wide overlapped impedance bandwidth and axial ratio bandwidth of 2.15–3.35 GHz (1.2 GHz, 43.6%) and a low height of 0.18
λ
0
at the center frequency of 2.7 GHz are achieved. Moreover, a high gain of 8.5–10.3 dBic and stable radiation patterns with no sidelobes and low back lobes of less than −20 dB are realized for wireless communication.
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This letter presents a beam-steering antenna controlled by gravity. It provides a new beam-steering mechanism. The maximum radiation direction could be adjusted by assigning the center of gravity of the ground. The coaxial feed li...
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This letter presents a beam-steering antenna controlled by gravity. It provides a new beam-steering mechanism. The maximum radiation direction could be adjusted by assigning the center of gravity of the ground. The coaxial feed line and ground are separated, granting the ability for rotation between the two components. As the verification, based on the proposed structure, a prototype Yagi–Uda antenna working at 2.45 GHz is manufactured and measured. The antenna realized 360° rotation, and the peak gain is 6.8 dBi. Passive beam control could be achieved, and the variation of the gain in the desired direction is within 0.2 dB during steering. The simulation results of the antenna prototype agree with the measured ones. This simple and practical structure provides a new solution for systems, which demand adaptive antenna beam in certain directions.
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摘要 :
This letter presents a lower band (LB) dipole antenna with a dual-band spatial filtering response for base station applications. The proposed LB dipole antenna has four square loop arms, each square loop arm is integrated by two t...
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This letter presents a lower band (LB) dipole antenna with a dual-band spatial filtering response for base station applications. The proposed LB dipole antenna has four square loop arms, each square loop arm is integrated by two types of split-ring structures. Each split-ring structure can be used to form a spatial bandpass response at one upper band. As a result, the LB antenna can realize electromagnetic transparent property at two upper bands while maintaining the performance at LB. For demonstration, a triband aperture-shared antenna array, operating at the LB of 0.69–0.96 GHz, middle band (MB) of 1.7–2.7 GHz, and the higher band (HB) of 3.3–3.8 GHz, is fabricated and measured. The simulated and measured results show that the S-parameters and radiation patterns of the HB and MB antennas change slightly compared to those of the subarray alone, verifying the effectiveness of the design method. The proposed LB antenna is suitable for compact multiband aperture-shared arrays, especially for 2G/3G/4G and 5G integration base station arrays.
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