• Title/Summary/Keyword: Fractional bandwidth

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Study on Coverage Analysis using Interference Cancellation in WCDMA System (WCDMA시스템에서 간섭제거기를 적용한 통화권 분석에 관한 연구)

  • 박태준;박재원;박용완
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.7
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    • pp.693-701
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    • 2002
  • In this paper, we analyze the coverage of asynchronous IMT(International Mobile Telecommunication)-2000 reverse link with a MUD(Multi-User Detector) system. The MUD system is utilized to increase the coverage of reverse link. Also we have considered a propagation loss model and an interference effect. Because it is very difficult that we have calculated the interference accurately, so a fractional cell loading factor(F) is used in this paper. We make use of a MUD efficiency($\beta$) to analyze the performance; this efficiency is presented the MAI of reduction. A simulation utilizes Hata's model, we calculated the coverage according to voice and data services. In this paper, we have assumed that the frequency of carrier has 800 MHz or 1.9 GHz, and a bandwidth is decided 3.84 MHz. We have predicted the performance of actual system by the analysis of capacity and coverage.

Design of a Compact Narrow Band Pass Filter Using the Circular CSRR (원형 CSRR를 이용한 소형 협 대역통과 필터 설계)

  • Choi, Dong-Muk;Kim, Dang-Oh;Kim, Che-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.11A
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    • pp.918-923
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    • 2009
  • In this paper, a design method of the compact narrow band filter on the microstrip board is proposed using complementary split-ring resonators(CSRRs). The design technique of this filter is based on cascading filter stages consisting of the combination of circular CSRRs, capacitive gaps between patches, and inductive grounded stubs with the meander configuration. By these means, it was possible to get the nearly symmetric frequency responses, adjustable bandwidths, compact sizes. And also excellent characteristic of the out-of-band rejection is achieved in contrast to the conventional filter design technique. The measured insertion shows good results about -4.0dB at the center frequency($f_0=1GHz$) and passband return loss is less than -9.4dB. The 3dB fractional bandwidth(FBW) is approximately 4%. The results of the frequency response measured on the fabricated band pass filter substrate show satisfactory agreement with the simulated frequency responses by the HFSS in the region of interest.

Scan Element Pattern and Scan Impedance of Open-Ended Waveguide Away Antenna (개방형 도파관 배열 안테나의 조향 소자 패턴 및 조향 임피던스에 관한 연구)

  • Yu, Je-Woo;Rah, Dong-Kyoon;Kim, Dong-Seok;Kim, Chan-Hong;Park, Dong-Chul
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.1 s.116
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    • pp.7-14
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    • 2007
  • In this paper, the scan characteristics of phased array antenna consisted of rectangular open-ended waveguide with a triangular grid are investigated. An infinite array structure is analyzed by numerically solving the integral equation for the electric field over the waveguide aperture using waveguide mode function and Floquet mode function. Next, SEP(Scan Element Pattern) and SI(Scan Impedance) characteristics are simulated by CST's MWS(Microwave Studio) and Ansoft's HFSS(High Frequency Structure Simulator) for the finite and infinite array structures. Also, validity of these approaches is verified by comparing the calculated and simulated results with the measured ones for an $8{\times}8$ subarray. Within 10.5 % fractional bandwidth in the X-band, the fabricated subarray showed the flat gain characteristic in the scan range of ${\pm}45^{\circ}C$ in the E-plane(azimuth) and ${\pm}20^{\circ}C$ in the H-plane(elevation), and also showed the return loss characteristic of less than -10 dB.

Design and Fabrication of A Wide-Band Dual-Polarization Stacked Patch Array Antenna for Satellite SAR Applications (위성 SAR용 광대역 이중편파 적층형 패치 배열 안테나 설계 및 제작)

  • Lee, Jae-Min;Yu, Je-Woo;Chae, Heeduck;Lee, YuRi;Jung, Hwa-Young;Kim, JongPil;Park, Jongkuk
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.20 no.2
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    • pp.72-78
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    • 2021
  • This paper proposes a wide-band dual-polarization stacked patch array antenna for satellite SAR system applications. The array antenna was designed for loss minimization and wide-band characteristics to enhance the performance of the SAR system and optimize it for active return loss in applications to active phased arrays. The fabricated array antenna showed a performance of 19.26%/19.79% fractional bandwidth within the -10 dB reference level of the active return loss and showed loss characteristics of 0.797 dB/0.799 dB averaged within the operational frequency for both H/V-polarization cases. The pattern performance was verified by comparing the measured patterns with the calculated patterns obtained by the array factor.

A study on characteristics of High Efficiency and Wideband Microstrip Band Pass Filter for Wireless Data Communication (무선데이터 통신을 위한 고효율 광대역 마이크로스트립 대역통과 필터 특성에 관한 연구)

  • Lee, Young-Hun;Song, Sung-Hae;Park, Won-Woo;Lee, Sang-Jae
    • Journal of IKEEE
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    • v.12 no.4
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    • pp.225-233
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    • 2008
  • This paper presents a compact, low insertion loss, sharp rejection and wide band microstrip band pass filter that is composed rectangular loop resonator and step-impedance-open-stub(SIOS) for wireless data communication. The SIOS can be reduce length about 30% more than general 0.25${\lambda}$ stub. And stubs can have the advantage of tuning impedance magnitude. In order to demonstrate agrement of this paper prove, the optimized wide band pass filters are realized and experimented. A transmission line model used to calculate the frequency response of the new filters shows good agreement with measurements. The filter with perturbation stubs has four poles at rejection band, the poles are excited 3.610GHz, 4.265GHz at low frequency band, 8.494GHz, 9.056GHz at high frequency band. And the filter has 3dB fractional bandwidth of 57%(3.695GHz), an insertion loss of better than 0.37dB from 4.549GHz to 8.244GHz, and two rejection of greater than 30dB within 237MHz(4.312GHz${\sim}$ 4.549GHz) at low frequency band, 234MHz(8.244GHz-8.491GHz) at high frequency band.

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Characteristics for High Efficiency and Wideband Band Pass Filter Using Rectangular Resonator and Step-Impedance-Open-Stubs (구형 공진기와 계단 임피던스 개방 스터브를 사용한 고효율 광대역 대역 통과 필터 특성)

  • Lee, Young-Hun;Kwon, Won-Hyun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.2
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    • pp.200-207
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    • 2009
  • This paper presents a compact, low insertion loss, sharp rejection and wide band microstrip band pass filter that is composed rectangular loop resonator and Step-Impedance-Open-Stub(SIOS). The SIOS can be reduce length about 30 % more than general 0.25 $\lambda$ open stub. And the stub can the advantage of tuning impedance magnitude. In order to demonstrate agrement of this paper prove, the optimized wide band pass filters are realized and experimented. A transmission line model used to calculate the frequency response of the new filters shows good agreement with measurements. The filter has 3 dB fractional bandwidth of 51.75 %(3.206 GHz), an insertion loss of better than 0.44 dB from 4.587 GHz to 7.793 GHz, and two rejection of greater than 30 dB within 221 MHz($4.326{\sim}4.587\;GHz$) at low frequency band, 181 MHz($7.739{\sim}7.954\;GHz$) at high frequency band. Maximum rejection characteristics of the filter are -61.8 dB at low frequency and -76.3 dB at high frequency.

A Design of the UWB Bandpass Filter with a Good Performance of the Stopband, and Notched Band in Passband (우수한 차단 대역 특성과 통과 대역 내에 저지 대역을 갖는 UWB 대역 통과 필터 설계)

  • An, Jae-Min;Kim, Yu-Seon;Pyo, Hyun-Seong;Lee, Hye-Sun;Lim, Yeong-Seog
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.1
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    • pp.28-35
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    • 2010
  • In this paper, we designed and fabricated a ultra-wideband(UWB) bandpass filter with a good performance of a stopband, and a notched band in passband. The transformed equivalent circuit of the highpass filter was realized by distributed element. A wide-passband with 3-dB fractional bandwidth of more than 100 % was achieved by using optimum response of the HPF. For improving lower and upper stopband characteristic, a cross coupling between feed lines was employed, which was analyzed by desegmentation technique. In order to reject interference of Wireless LAN and Hyper LAN(5.15~5.825 GHz), the narrow notched(rejection) band was realized by a spurline. The fabricated BPF indicated the passband from 3.1 to 10.55 GHz and the flat group delay of less than 0.94 ns over the entire passband except the rejection band. The filter shown sharp attenuation both inside and outside the band and notched band from 5.2 to 6.12 GHz.

Design and Implementation of Compact Ultra Wideband Patch Antenna Using L-Feed and Slot-Feed (L 급전 및 Slot 급전을 동시에 적용하는 광대역 소형 패치 안테나의 설계 및 구현)

  • Choi, Jong-In;Lee, Bomson
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.5
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    • pp.484-491
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    • 2013
  • In this paper, the method of designing a wideband antenna has been introduced through the design technique that simultaneously employs L- and slot-type feeds. Using the two kinds of feeds and additional fence structure, a compact wideband patch antenna has been realized. The size of the patch has been reduced by about 30 % based on the low frequency(824 MHz) and the full fractional bandwidth is wider than 100 %. The L-feed element is for the EM coupling feeding at the low frequency, while it functions as a feeding line for the power coupling through the slot at the high frequency. The proposed antenna has been designed not only for wideband operations but also for a proper array element with a reduced size. Thus, the foundation for developing the ultra wideband patch array antennas has been prepared. The fabricated antenna has been found to have good characteristics on V.S.W.R and the radiation patterns over the full bands. The experimental and computed results are shown to be in good agreement.

A Study on the MDAS-DR Antenna for Shaping Flat-Topped Radiation Pattern (구형 빔 패턴 형성을 위한 MDAS-DR 안테나에 대한 연구)

  • Eom, Soon-Young;Yun, Je-Hoon;Jeon, Soon-Ick;Kim, Chang-Joo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.3 s.118
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    • pp.323-333
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    • 2007
  • In this paper, a new MDAS-DR antenna structure designed to efficiently shape a flat-topped radiation pattern is proposed. The antenna structure is composed of a stacked micro-strip patch exciter and a multi-layered disk array structure(MDAS) surrounded by a dielectric ring. The MDAS, which was supplied by a stacked microstrip patch exciter with radiating power, can form a flat-topped radiation pattern in a far field by a mutual interaction with the surrounding dielectric ring. Therefore, the design parameters of the dielectric ring and the MDAS structure are important design parameters for shaping a flat-topped radiation pattern. The proposed antenna used twelve multi-layered disk array elements and a Teflon material with a dielectric constant of 2.05. An antenna operated at 10 GHz$(9.6\sim10.4\;GHz)$ was designed in order to verify the effectiveness of the proposed antenna structure. The commercial simulator of CST Microwave $Studio^{TM}$, which was adapted to a 3-D antenna structure analysis, was used for the simulation. The antenna breadboard was also fabricated and its electrical performance was measured in an anechoic antenna chamber. The measured results of the antenna breadboard with a flat-topped radiation pattern were found to be in good agreement with the simulated one. The MDAS-DR antenna gain measured at 10 GHz was 11.18 dBi, and the MDAS-DR antenna was capable of shaping a good flat-topped radiation pattern with a beam-width of about $40^{\circ}$, at least within a fractional bandwidth of 8.0 %.

Dielectric Waveguide Filters Design Embedded in PCB Substrates using Via Fence at Millimeter-Wave (밀리미터파 대역에서 Via Fence를 이용한 PCB 기판용 유전체 도파관 필터 설계)

  • 김봉수;이재욱;김광선;강민수;송명선
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.1
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    • pp.73-80
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    • 2004
  • In this paper, the implementation and embedding method of the existing air-filled waveguide-filters at millimeter-wave on general PCB substrate is introduced by systematically inserting the vias inside waveguide and mathematically manipulating the simple equations obtained ken the classical circular-post waveguide filter design. All the metal structures placed vertically such as side wall fur perfect ground plane and circular-post for signal control in the air-filled WR-22 waveguide are replaced with several types of via for constructing the bandpass-filter. Side wall and poles inside waveguide are realized by placing a series array of via and tuning the via diameter. The lengths of x, y, z axis are reduced in proportion to root square of employed substrate dielectric constant and especially the length of z axis can be more reduced due to the characteristics of the wave propagation. Because the mass production on PCB is possible without fabricating a large-scaled metal waveguide of WR-22 as input/output ports at millimeter-wave regime, the manufacturing cost is reduced considerably. Finally, when using multilayer process like LTCC for small-sized module, it is one of advantages to use only one layer f3r the filter fabrication. To evaluate the validity of this novel technique, order-3 Chebyshev BPF(Bandpass-Filter) centered at 40 GHz-band with a 2.5 % FBW (Fractional Bandwidth) were used. The employed substrate has relative dielectric constant of 2.2 and thickness of 10 mil of Rogers RT/Duroid 5880. Accroding to design and measurement results, a good performance of insertion loss of 2 ㏈ and return loss of -30 ㏈ is achieved at full input/output ports.