The Experts below are selected from a list of 15582 Experts worldwide ranked by ideXlab platform
Mingjian Li - One of the best experts on this subject based on the ideXlab platform.
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polarization reconfigurable magnetoelectric Dipole Antenna for 5g wi fi
IEEE Antennas and Wireless Propagation Letters, 2017Co-Authors: Lei Ge, Dengguo Zhang, Xujun Yang, Mingjian Li, Hang WongAbstract:A novel polarization-reconfigurable aperture-coupled magnetoelectric (ME) Dipole Antenna is presented. By electronically controlling the state of switches between square patches and an additional strip of the ME Dipole, the Antenna is capable of switching the polarization among one linearly polarized (LP) and two orthogonal circularly polarized states. A fully functional prototype is developed and tested, demonstrating the Antenna with an overlapped bandwidth of 16% from 5.07 to 5.95 GHz for both $S$ 11 ≤ –10 dB and axial ratio (AR) ≤ 3 dB. A measured gain of approximately 8.2 dBi and a radiation efficiency of approximately 85% over the overlapped band are obtained for all polarization states. Moreover, due to advantages of the ME Dipole, the proposed design is able to realize stable radiation patterns with both cross-polarization and back-radiation levels lower than –13 dB. With all these features, the proposed design is very attractive for 5G Wi-Fi applications.
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Miniaturization of Magnetoelectric Dipole Antenna by Using Metamaterial Loading
IEEE Transactions on Antennas and Propagation, 2016Co-Authors: Mingjian Li, Kwai-man Luk, Lei Ge, Kuang ZhangAbstract:This communication presents a novel miniaturized magneto- electric Dipole Antenna by introducing magnetic metamaterial loading. The proposed Antenna, excited by a Γ-shaped probe, consists of a planar electric Dipole and a quarter-wave shorted patch Antenna. To miniaturize the Antenna, the metamaterial loading is fully arranged inside the shorted patch Antenna and the matching portion of the Γ-shaped probe. The loading is formed by a stack of modified rectangular split-ring resonators which are placed very closely in parallel. With the presence of the metamaterials, the effective permeability of the substrate is increased, and therefore the Antenna finds a significant size reduction. Most importantly, the impedance and radiation characteristics of the Antenna are not compromised too much. The Antenna loaded with metamaterials exhibits an impedance bandwidth of 44% ranging from 1.7 to 2.67 GHz and a boresight gain of about 8.5 dBi. The volume size is reduced by 48% when compared with the original design having an impedance bandwidth of 47%.
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wideband magneto electric Dipole Antenna for 60 ghz millimeter wave communications
IEEE Transactions on Antennas and Propagation, 2015Co-Authors: Mingjian LiAbstract:A new wideband magneto-electric Dipole Antenna is proposed for 60-GHz millimeter-wave applications. This Antenna features wideband and stable gain characteristics. The low cross polarization and low back radiation are obtained owing to its complementary Antenna structure. The prototype of the single element was built using the low-cost single-layer printed circuit board (PCB) technology. The proposed Antenna exhibits an impedance bandwidth of 51% ( ${\rm SWR} \leq 2$ ) and a gain of approximately 8 dBi.
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a differential fed magneto electric Dipole Antenna for uwb applications
IEEE Transactions on Antennas and Propagation, 2013Co-Authors: Mingjian LiAbstract:A new magneto-electric Dipole Antenna with a unidirectional radiation pattern is proposed. A novel differential feeding structure is designed to provide an ultra-wideband impedance matching. A stable gain of 8.25±1.05 dBi is realized by introducing two slots in the magneto-electric Dipole and using a rectangular box-shaped reflector, instead of a planar reflector. The Antenna can achieve an impedance bandwidth of 114% for SWR ≤ 2 from 2.95 to 10.73 GHz. Radiation patterns with low cross polarization, low back radiation, fixing broadside direction mainbeam and symmetrical E- and H -plane patterns are obtained over the operating frequency range. Moreover, the correlation factor between the transmitting Antenna input signal and the receiving Antenna output signal is calculated for evaluating the time-domain characteristic. The proposed Antenna, which is small in size, can be constructed easily by using PCB fabrication technique.
Zaiping Nie - One of the best experts on this subject based on the ideXlab platform.
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A Compact Dual-Polarized Printed Dipole Antenna With High Isolation for Wideband Base Station Applications
IEEE Transactions on Antennas and Propagation, 2014Co-Authors: Yanshan Gou, Jinxin Li, Shiwen Yang, Zaiping NieAbstract:A compact dual-polarized printed Dipole Antenna for wideband base station applications is presented in this communication. The proposed Dipole Antenna is etched on three assembled substrates. Four horizontal triangular patches are introduced to form two Dipoles in two orthogonal polarizations. Two integrated baluns connected with 50 Ω SMA launchers are used to excite the Dipole Antenna. The proposed Dipole Antenna achieves a more compact size than many reported wideband printed Dipole and magneto-electric Dipole Antennas. Both simulated and measured results show that the proposed Antenna has a port isolation higher than 35 dB over 52% impendence bandwidth (VSWR <; 1.5). Moreover, stable radiation pattern with a peak gain of 7 dBi - 8.6 dBi is obtained within the operating band. The proposed Dipole Antenna is suitable as an array element and can be used for wideband base station Antennas in the next generation IMT-advanced communications.
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a novel broadband printed Dipole Antenna with low cross polarization
IEEE Transactions on Antennas and Propagation, 2007Co-Authors: Zhanwei Zhou, Shiwen Yang, Zaiping NieAbstract:A novel broadband printed Dipole Antenna with low cross-polarization is presented. The printed Dipole employs a double-layered structure where the E-field component perpendicular to the Dipole arms is minimized, thus low cross-polarization is obtained. Measurement results show that the printed Dipole Antenna achieves a bandwidth up to 50% while reducing the cross-polarization level to less than -30 dB within the frequency band.
R D Averitt - One of the best experts on this subject based on the ideXlab platform.
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terahertz radiation induced sub cycle field electron emission across a split gap Dipole Antenna
Applied Physics Letters, 2015Co-Authors: Jingdi Zhang, Xiaoguang Zhao, Xiaoning Wang, Gufeng Zhang, Kun Geng, Xin Zhang, R D AverittAbstract:We use intense terahertz pulses to excite the resonant mode (0.6 THz) of a micro-fabricated Dipole Antenna with a vacuum gap. The Dipole Antenna structure enhances the peak amplitude of the in-gap THz electric field by a factor of ∼170. Above an in-gap E-field threshold amplitude of ∼10 MV/cm−1, THz-induced field electron emission is observed as indicated by the field-induced electric current across the Dipole Antenna gap. Field emission occurs within a fraction of the driving THz period. Our analysis of the current (I) and incident electric field (E) is in agreement with a Millikan-Lauritsen analysis where log (I) exhibits a linear dependence on 1/E. Numerical estimates indicate that the electrons are accelerated to a value of approximately one tenth of the speed of light.
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terahertz radiation induced sub cycle field electron emission across a split gap Dipole Antenna
arXiv: Optics, 2015Co-Authors: Jingdi Zhang, Xiaoguang Zhao, Xiaoning Wang, Gufeng Zhang, Kun Geng, Xin Zhang, Kebin Fan, R D AverittAbstract:We use intense terahertz pulses to excite the resonant mode (0.6 THz) of a micro-fabricated Dipole Antenna with a vacuum gap. The Dipole Antenna structure enhances the peak amplitude of the in-gap THz electric field by a factor of ~170. Above an in-gap E-field threshold amplitude of ~10 MVcm-1, THz-induced field electron emission is observed (TIFEE) as indicated by the field-induced electric current across the Dipole Antenna gap. Field emission occurs within a fraction of the driving THz period. Our analysis of the current (I) and incident electric field (E) is in agreement with a Millikan-Lauritsen analysis where log (I) exhibits a linear dependence on 1/E. Numerical estimates indicate that the electrons are accelerated to a value of approximately one tenth of the speed of light.
Hang Wong - One of the best experts on this subject based on the ideXlab platform.
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polarization reconfigurable magnetoelectric Dipole Antenna for 5g wi fi
IEEE Antennas and Wireless Propagation Letters, 2017Co-Authors: Lei Ge, Dengguo Zhang, Xujun Yang, Mingjian Li, Hang WongAbstract:A novel polarization-reconfigurable aperture-coupled magnetoelectric (ME) Dipole Antenna is presented. By electronically controlling the state of switches between square patches and an additional strip of the ME Dipole, the Antenna is capable of switching the polarization among one linearly polarized (LP) and two orthogonal circularly polarized states. A fully functional prototype is developed and tested, demonstrating the Antenna with an overlapped bandwidth of 16% from 5.07 to 5.95 GHz for both $S$ 11 ≤ –10 dB and axial ratio (AR) ≤ 3 dB. A measured gain of approximately 8.2 dBi and a radiation efficiency of approximately 85% over the overlapped band are obtained for all polarization states. Moreover, due to advantages of the ME Dipole, the proposed design is able to realize stable radiation patterns with both cross-polarization and back-radiation levels lower than –13 dB. With all these features, the proposed design is very attractive for 5G Wi-Fi applications.
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substrate integrated magneto electric Dipole Antenna for 5g wi fi
IEEE Transactions on Antennas and Propagation, 2015Co-Authors: Hang WongAbstract:In this communication, a new technique—tapered H-shaped ground, is proposed to reduce the thickness of a magneto-electric (ME) Dipole Antenna. By employing the proposed technique, the Antenna height of the ME Dipole Antenna is reduced from 0.25 to 0.11 $\lambda_{{\bf 0}}$ (where $\lambda_{{\bf 0}}$ is the wavelength of 5.5 GHz). This new Antenna structure can be easily realized by the multi-layer printed circuit board (PCB) technology, which is low cost and easy to fabricate. Measured results show that this Antenna has an impedance bandwidth of 18.74% for ${\rm VSWR} \le 2$ (4.98 to 6.01 GHz). Stable radiation patterns with low back radiation and low cross polarization radiation are achieved across the entire operating bandwidth for 5G Wi-Fi.
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a wideband circularly polarized cross Dipole Antenna
IEEE Antennas and Wireless Propagation Letters, 2014Co-Authors: Hang WongAbstract:This letter introduces a wideband circularly polarized (CP) cross-Dipole Antenna fabricated on a double-layered printed circuit board (PCB) substrate for 2.45-GHz ISM band wireless communications. Unlike conventional cross-Dipole Antennas, the proposed cross Dipole is designed with wide open ends such that both impedance and axial-ratio (AR) bandwidths are enhanced. In addition, to excite the CP radiation effectively, a curved-delay line providing an orthogonal phase difference among the cross-Dipole elements is attached at the corners of the sequentially rotated elements. By choosing a proper radius of the curved-delay line, a wide input impedance of the Antenna can be realized. The Antenna is center-fed by a 50- Ω coaxial cable and is placed above a square reflector to obtain a directional CP radiation pattern. With the advantage of centered feed, symmetric CP radiation patterns can be achieved across the entire operating bandwidth. Simulated and measured results confirm the proposed Antenna produced good CP characteristics. An impedance bandwidth (for VSWR ≤ 2) of about 50.2% (1.99-3.22 GHz) and the 3-dB AR bandwidth of about 27% (2.30-2.9 GHz) around the center frequency of 2.45 GHz were measured. The Antenna has an average CP gain of 6.2 dBic across the operating bandwidth and the maximum gain of 6.8 dBic at the center frequency. The size of Antenna is 0.45λ×0.45λ×0.24λ.
Yongmei Pan - One of the best experts on this subject based on the ideXlab platform.
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compact broadband dual polarized filtering Dipole Antenna with high selectivity for base station applications
IEEE Transactions on Antennas and Propagation, 2018Co-Authors: Chao Feng Ding, Yao Zhang, Xiu Yin Zhang, Yongmei Pan, Quan XueAbstract:This paper presents a broadband dual-polarized filtering Dipole Antenna for base-station application, which has a compact size of 50 $\text {mm} \times 50\,\,\text {mm} \times 31.8$ mm. The Antenna consists of four parts: main radiator, feeding baluns, reflector, and two parasitic loops. Without using complex filtering circuits, the dual-polarized Dipole Antenna realizes satisfactory filtering performance and enhanced bandwidth by employing only two parasitic loops. Two specific radiation nulls are thus generated and individually controlled by the two parasitic loops. To further improve the upper stopband selectivity and bandwidth, a simple open-ended stub is added to the arms of the Dipole. As a result, the bandwidth can be tuned from 7.4% to 47.6%, and the realized gain is decreased dramatically from 8.6 dBi at 2.7 GHz (in-band) to −10 dBi at 2.9 GHz (out-of-band). For demonstration, a broadband dual-polarized Dipole Antenna is implemented. Measured results show that the proposed Antenna has more than 34 dB port isolation over 48.7% (1.66–2.73 GHz) impendence bandwidth (VSWR < 1.5). The measured in-band gain is about 8.15 dBi with stable 3 dB beamwidth 65.4°±2.4° in the horizontal plane, whereas the out-of-band radiation suppression is more than 17 dB.
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low profile planar filtering Dipole Antenna with omnidirectional radiation pattern
IEEE Transactions on Antennas and Propagation, 2018Co-Authors: Yao Zhang, Xiu Yin Zhang, Yongmei PanAbstract:This paper presents a low-profile planar Dipole Antenna with omnidirectional radiation pattern and filtering response. The proposed Antenna consists of a microstrip-to-slotline transition structure as the feeding network and a planar Dipole as the radiator. Filtering response is obtained by adding nonradiative elements, including a coupled U-shaped microstrip line and two I-shaped slots, to the feeding network. Within the operating passband, the added nonradiative elements do not work, and thus the in-band radiation performance of the Dipole Antenna is nearly not affected. However, at the side stopbands, the added elements resonate and prevent the signal passing through the feeding network to the Dipole Antenna, suppressing the out-of-band radiation significantly. As a result, both satisfactory filtering and radiation performances are obtained. For demonstration, an omnidirectional filtering Dipole Antenna is implemented. Single-band bandpass filtering responses in both the reflection coefficient and realized gain are obtained. The measured in-band gain is ~2.5 dBi, whereas the out-of-band radiation suppression is more than 15 dB.
