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Author

Ji Yuefeng

Bio: Ji Yuefeng is an academic researcher from Beijing University of Posts and Telecommunications. The author has contributed to research in topics: Patch antenna & Antenna (radio). The author has an hindex of 4, co-authored 6 publications receiving 66 citations.

Papers
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Journal ArticleDOI
TL;DR: In this paper, two methods in terms of bandwidth broadening are proposed and compared for monopole slot ultrawideband (UWB) antennas supporting mobile terminal applications, and the comparison of gain characters as well as the radiation patterns are discussed at the bands of interest.
Abstract: Two methods in terms of bandwidth broadening are proposed and compared for monopole slot ultrawideband (UWB) antennas supporting mobile terminal applications. The original antenna has a bandwidth of 9.27 GHz (1.73-11 GHz) that covers PCS1900, UMTS2000, TD-SCDMA, WLAN 802.11b/g or Bluetooth, LTE, WiMAX, and UWB frequency range. In this letter, by cutting two new slots on the ground plane, the antenna can expand its bandwidth to 9.33 GHz (1.67-11 GHz) that is available at extra DVB-H, DCS1800 services. Meanwhile, the bandwidth of the antenna with conventional mushroom-type electromagnetic band-gap (CMT-EBG) embedded on both sides of a 50- Ω microstrip line can be enhanced to 9.47 GHz (1.53-11 GHz) with the extra GPS covered. The largest impedance bandwidth of 151% can be obtained. Moreover, the comparisons of gain characters as well as the radiation patterns are discussed at the bands of interest. It is illustrated that the gain of the antenna based on CMT-EBG is higher than other two cases except to the range of 5.19-5.93 GHz and the radiation patterns are basically identical. The antennas are fabricated on FR4 substrate, and the deviations between measured results and simulated results are discussed.

60 citations

Patent
23 Oct 2013
TL;DR: In this paper, a high-gain G-shaped dual-frequency monopole antenna with a loaded dual frequency AMC reflection plate was designed for a dual-channel WLAN system.
Abstract: The invention relates to a high-gain G-shaped dual-frequency monopole antenna with a loaded dual-frequency AMC reflection plate, and belongs to the technical field of electromagnetism propagation and receiving According to the micro-strip-line-feed G-shaped dual-frequency monopole antenna with the loaded dual-frequency AMC reflection plate, the dual-frequency AMC reflection plate is loaded under the G-shaped dual-frequency antenna The antenna is characterized in that under the condition that the section of the antenna is kept low, the maximum gain of a 24-GHz frequency band and a 52-GHz frequency band in a WLAN system reaches 72dBi, and backward radiation of the 24-GHz frequency band and the 52-GHz frequency band in the WLAN system reduces by 141dB and 137dB respectively The designed high-gain dual-frequency antenna with the loaded AMC reflection plate can be used for a 24-GHz system (24GHz-248GHz) and a 52-GHz system (515 GHz-535GHz) in the WLAN system, and provides guidance for a high-gain antenna working in a dual-frequency WLAN system

6 citations

Patent
28 Aug 2013
TL;DR: In this article, a double-frequency high-gain coaxial feed patch antenna is presented, which can simultaneously work at two frequency bands of 2.45 GHz and 5.8 GHz.
Abstract: The invention provides a high-gain antenna which can simultaneously work at two frequency bands of 2.45 GHz and 5.8GHz and a method for realizing the high-gain antenna, which belong to the technical field of electromagnetic propagation and receiving. A double-frequency high-gain coaxial feed patch antenna provided by the invention comprises a rectangular thin metal patch, a metal earth plate and two EBG (electromagnetic band gaps) coatings. The method specifically comprises steps of loading the EBG coatings right above the coaxial feed patch antenna. The coaxial feed patch antenna is characterized in that a loaded EBG coating structure has specific dimensions and arrangement, and a specific distance is left between the two EBG coatings and a metal earth plate of the antenna. The gains of two working frequency bands of the antenna are effectively increased through the loaded EBG coating structures; and moreover, the EBG coating structures and the patch antenna can be respectively designed, and a double-frequency high-gain antenna designing process is simplified. The antenna provided by the invention can work at two frequency bands of 2.45 GHz and 5.8GHz and is particularly suitable for application occasions with high directional requirements. Guidance is provided for designing the multi-frequency high-gain antenna through utilizing the method provided by the invention.

4 citations

Patent
23 Jul 2014
TL;DR: In this article, a three-stop-band notch ultra-wideband antenna with stop-band units simultaneously loaded to a feeder and a radiation patch is proposed, which is capable of filtering out interferences from WiMAX (Worldwide Interoperability for Microwave Access) (3.3-3.6GHz) and WLAN (Wireless Local Area Network) (5.15-5.35GHz) systems.
Abstract: The invention relates to the design of a notch ultra-wideband antenna and belongs to the technical field of propagating and receiving electromagnetic waves. The invention provides a novel multi-notch ultra-wideband antenna with stop-band units simultaneously loaded to a feeder and a radiation patch; specifically speaking, an open slot of 1/4 wavelength is formed in the radiation patch and C-shaped half-wavelength open-circuit resonance units different in size are loaded at the two sides of the feeder, and therefore, a three-stop-band notch ultra-wideband antenna is realized; the three-stop-band notch ultra-wideband antenna is capable of filtering out interferences from WiMAX (Worldwide Interoperability for Microwave Access) (3.3-3.6GHz) and WLAN (Wireless Local Area Network) (5.15-5.35GHz, 5.725-5.825GHz) systems. The antenna has the advantages of independently adjustable frequency point of each stop-band and independently adjustable bandwidth of each stop-band. Simulation results and actual measurement results prove excellent multi-frequency filter characteristic of the antenna.

4 citations

Patent
23 Jul 2014
TL;DR: In this paper, the authors proposed a BSIS-UC-EBG (Bidirectional Symmetrical I-shaped Slot Uniplanar-Compact Electromagnetic Band-Gap) structure in a millimeter wave antenna and belongs to the technical field of electromagnetic transmission and receiving.
Abstract: The invention relates to a BSIS-UC-EBG (Bidirectional Symmetrical I-shaped Slot Uniplanar-Compact Electromagnetic Band-Gap) structure in a millimeter wave antenna and belongs to the technical field of electromagnetic transmission and receiving. The BSIS-UC-EBG structure is characterized in that I-shaped slots are formed in the horizontal direction and the vertical direction through cascade connection and are symmetrical to each other, the design is simple, the structure is compact, and the frequency can be adjusted according to the actual application, as shown in figure. The BSIS-UC-EBG structure is located around a radiation main body of a patch antenna and accordingly the size and the profile of the patch antenna can be maintained to be unchanged and the bandwidth and the gain of the antenna are effectively improved. According to the result, the bandwidth of the minus 10 dB of the BSIS-UC-EBG structure is 49.3 to 71.4 GHz, the BSIS-UC-EBG can be applied to a millimeter wave WLAN (Wireless Local Area Network) system, and the gain of the 60 GHz is 4.7 dBi. Compared with electromagnetic band-gap structure unloaded antennas, the relative bandwidth is improved by 16.4% and the gain is improved by about 10 dB.

2 citations


Cited by
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Journal ArticleDOI
TL;DR: Comparative parameters in terms of electrical dimension, bandwidth, Fractional bandwidth (FB) and Bandwidth Dimension Ratio (BDR) are presented which introduces the researchers to the technical challenges in the design of a compact wideband antenna.
Abstract: With the recent advancement and phenomenal progress in the field of wireless communication technology, there is an ever increasing demand for high data rates and improved quality of service for the end users. In recent times various designs of super wideband antennas (SWB) fulfilling diverse objectives have been proposed for modern wireless networks. Design of compact and wideband antenna for high speed, high capacity, and secure wireless communications presents a challenging task for designers of fixed and mobile wireless communication systems. In this paper, a comprehensive review concerning antenna structures and the technologies adopted for design and analysis of SWB antennas for wireless application is reported. Comparative parameters in terms of electrical dimension, bandwidth, Fractional bandwidth (FB) and Bandwidth Dimension Ratio (BDR) are presented which introduces the researchers to the technical challenges in the design of a compact wideband antenna. This paper contributes to present existing novel approaches along with its adequacy in the design techniques. This review exercise will assist the researchers with valuable support for further research and to achieve better impedance matching, wide bandwidth, high gain and good efficiency along with well directive radiation characteristics.

59 citations

Journal ArticleDOI
TL;DR: In this paper, a simple broadband planar monopole microstrip patch antenna with curved slot and partial ground plane is proposed for 2.4/5.8 GHz WLAN bands, 2.5/3.5 GHz WiMAX bands, and other wireless communication services.
Abstract: This paper presents a simple broadband planar monopole microstrip patch antenna with curved slot and partial ground plane. The proposed antenna is designed and fabricated on commercially available FR4 material with er = 4.3 and 0.025 loss tangent. Bandwidth enhancement has been achieved by introducing a curved slot in the patch and optimizing the gap between the patch and the partial ground plane and the gap between the curved slot and the edge of the patch. Simulated peak gain of the proposed antenna is 4.8 dB. The impedance bandwidth (defined by 10 dB return loss) of the proposed antenna is 109% (2–6.8 GHz), which shows bandwidth enhancement of 26% as compared with simple monopole antenna. The antenna is useful for 2.4/5.2/5.8-GHz WLAN bands, 2.5/3.5/5.5-GHz WiMAX bands, and other wireless communication services. Measured results show good agreement with the simulated results. The proposed antenna details are described and measured/simulated results are elaborated.

37 citations

Journal ArticleDOI
TL;DR: In this article, a two-semicircular slot-loaded monopole with a staircase ground structure is presented for automotive applications, which is a novel optically transparent multiple-input multiple-output (MIMO) antenna.
Abstract: A novel optically transparent multiple-input multiple-output (MIMO) antenna for automotive applications is presented in this article. The MIMO antenna consists of a two-semicircular slot-loaded monopole with a staircase ground structure. It is developed on a glass substrate with dimension $29\times50$ mm2. The fluorine-doped tin oxide and indium-doped tin oxide (ITO) are used as the conductive layers on the bottom and top of the substrate with sheet resistance $4~\Omega $ /sq and $10~\Omega $ /sq, respectively. The fabricated antenna has an optical transmittance greater than 72%; hence, it can be placed on the glass surface of the automotive. The measured results show that the proposed antenna exhibits a good impedance matching over a frequency of 2.4–11 GHz with isolation greater than 20 dB and a peak realized gain of 2 dBi, which is suitable for ultrawideband (UWB) automotive applications.

36 citations

Proceedings ArticleDOI
01 Sep 2016
TL;DR: A parametric study of the effects of different size and shapes of slots on the performance characteristic of UWB Microstrip antenna using a centrally loaded rectangular slot would be of a great interest in the designing of compact antennas for wireless communications operating in UWB.
Abstract: This research paper presents a simple design consideration of Ultra-Wide Band (UWB) Microstrip antenna using a centrally loaded rectangular slot. An analytical study of the effects of different size and shapes of slots on the performance characteristic of UWB Microstrip antenna is presented. Insertion of slot and the changes in dimension of ground plane has a high impact on the behavior and parameter of the patch antenna. To improve the bandwidth of the patch antenna, proper insertion of slot on the planer patch structure has been used. In the paper 12mm by 15.6 mm rectangular patch antenna carved on FR4 substrate is presented. Both the simulated and the measured result show the operation of the antenna in the entire UWB range. This parametric study would be of a great interest in the designing of compact antennas for wireless communications operating in UWB.

31 citations

Journal ArticleDOI
TL;DR: In this article, a corner truncated broadband patch antenna with circular slots is presented, and the proposed antenna is fabricated on 14 * 14 * 1.57 mm3 Rogers RT5870 substrate.
Abstract: In this communication, a corner truncated broadband patch antenna with circular slots is presented. The proposed antenna is fabricated on 14 * 14 * 1.57 mm3 Rogers RT5870 substrate (er = 2.33 and loss tangent of 0.0012) and a 50-Ω SMA connector is used for excitation. Bandwidth enhancement has been reported due to cutting of two circular slots and truncating the corners of the square patch, which gives rise to mode splitting phenomenon and better impedance matching. Simulated results show that the impedance bandwidth (S11 < 10 dB) of the proposed antenna is 19% (10.8–13.2 GHz). Measured results are in good agreement with the simulated results. The fractional bandwidth of the proposed antenna has enhanced from 8.5 to 19% as compared to the simple patch antenna, showing an enhancement of 123%. The peak gain of the proposed antenna is 7 dB. The antenna finds application in satellite communication, radar communication, and other alleged wireless communication services. Details and comparison of the proposed antenna with simple patch antenna have been described. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:845–849, 2015

29 citations