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Author

Luo Qun

Bio: Luo Qun is an academic researcher from Beijing University of Posts and Telecommunications. The author has contributed to research in topics: Antenna (radio) & Monopole antenna. The author has an hindex of 4, co-authored 8 publications receiving 89 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

Journal ArticleDOI
TL;DR: In this article, a unidirectional dual-band coplanar waveguide fed antenna (DB-CPWFA) loaded with a reflector is presented, which shows an effective dual operational bandwidth.
Abstract: A unidirectional dual-band coplanar waveguide fed antenna (DB-CPWFA) loaded with a reflector is presented in this paper. The reflector is made of an electric ground plane, a dielectric substrate, and artificial magnetic conductor (AMC) which shows an effective dual operational bandwidth. Then, the closely spaced AMC reflector is employed under the DB-DPWFA for performance improvement including unidirectional radiation, low profile, gain enhancement, and higher front-to-back (F/B) ratio. The final antenna design exhibits an 8% and 13% impedance bandwidths for 2.45 GHz and 5.8 GHz frequency regions, respectively. The overall gain enhancement of about 4 dB is achieved. The F/B ratio is approximate to 20 dB with a 16 dB improvement. The measured results are inconsistent with the numerical values. The presented design is a suitable candidate for radio frequency identification (RFID) reader application.

15 citations

Patent
12 Dec 2012
TL;DR: In this paper, a high-gain dielectric resonator antenna based on an H-shaped slot fractal uniplanar compact electromagnetic bandgap (HSF-UC-EBG) structure is proposed.
Abstract: The invention provides a high-gain dielectric resonator antenna applied to a 60 GHz millimeter wave communication system, belongs to the technical field of electromagnetic propagation and receiving and provides a high-gain dielectric resonator antenna based on an H-shaped slot fractal uniplanar compact electromagnetic bandgap (HSF-UC-EBG) structure. The specific implementation is that a circle of HSF-UC-EBG structure is loaded around a radiating main body of a dielectric resonator antenna; and the high-gain dielectric resonator antenna is characterized in that the gain in a working frequency range of the antenna is effectively improved under the conditions of keeping size and section of the dielectric resonator antenna unchanged. The designed high-gain HSF-UC-EBG dielectric resonator antenna can be used in the 60 GHz millimeter wave communication system and provides guidance for designing a high-gain antenna which works in a high-frequency system.

10 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

Journal ArticleDOI
TL;DR: In this paper, the arrangement of the alternately symmetrical unit cells of an H-shaped slot fractal uniplanar electromagnetic bandgap structure (HSF-UC-EBGs) is investigated.
Abstract: The arrangement of the alternately symmetrical unit cells of an H-shaped slot fractal uniplanar electromagnetic bandgap structure (HSF-UC-EBGs) is investigated in this study. It is shown that different bandgap characteristics can be obtained when the unit cells are arranged in different ways. Two bandgaps of 1.30–2.52 and 2.85–3.76 GHz are obtained when 5 unit cells are arranged along x direction, while a bandgap of 2.30–4.78 GHz is obtained when 5 unit cells are arranged along y direction. Therefore, one can predict that when the symmetrical unit cells and the 90° rotated symmetrical unit cells are arranged alternately, the bandgap will extend to the sum of the three bandgaps mentioned previously. Based on the study described previously, we design an ultra-wideband quasi-isotropic HSF-UC-EBGs and the measured results show that its relative bandwidth reach up to at least 105.4% GHz at 3.32 GHz.

4 citations


Cited by
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Book ChapterDOI
01 Jan 2002
TL;DR: This chapter contains sections titled: Introduction Background Physical Layer Link Layer EGPRS Performance Conclusions and References.
Abstract: This chapter contains sections titled: Introduction Background Physical Layer Link Layer EGPRS Performance Conclusions This chapter contains sections titled: References

112 citations

Journal ArticleDOI
TL;DR: In this article, a novel antenna structure enabled by a miniature high impedance surface (HIS) is proposed for smartwatch applications, which is the most compact HIS structure to date.
Abstract: A novel antenna structure enabled by a miniature high impedance surface (HIS) is proposed for smartwatch applications. The smartwatch antenna must be low-profile, highly directive, low specified absorption rate (SAR), and robust to the loading effect due to a human body. HISs are particularly suitable to cope with these design goals. However, an HIS is usually too electrically large to fit into the design space of smartwatch applications. Furthermore, the characterization of HISs is determined by observing the reflection phase of a unit cell, but this method becomes improper for finite-size and miniaturized HISs. In this letter, a new design method is presented. By using fractional factorial designs (FFD), the antenna performances are significantly enhanced even though the size of the HIS is only $0.3{\lambda _0}\times 0.3{\lambda _0}$ . Accordingly, the dimensions of the proposed antenna are $38 \times 38 \times 3 ~\hbox{mm}^3$ (at 2.4 GHz), which is the most compact HIS structure to date. The directivity of the antenna is 6.3 dBi, and the maximum 1 g averaged SAR value is only 0.29 W/kg for an input power of 100 mW; moreover, the radiation efficiency and impedance matching are very robust against the loading effect due to wrist tissue.

110 citations

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