• Title, Summary, Keyword: Dual-Band Operation

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Design of Miniaturized Dual-Band Artificial Magnetic Conductor with Easy Control of Second/First Resonant Frequency Ratio

  • Ta, Son Xuat;Park, Ikmo
    • Journal of electromagnetic engineering and science
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    • v.13 no.2
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    • pp.104-112
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    • 2013
  • A novel miniaturized artificial magnetic conductor (AMC) is proposed for dual-band operation. An AMC unit cell that employs four slots in the metallic patch is used to achieve miniaturization as well as easy control of the second/first resonant frequency ratio, which can be varied from 1.5 to 3.26 by simply changing the slot shape for a given metallic patch size. A dual-band antenna composed of a wideband monopole suspended over the proposed AMC surface is designed and tested to validate this approach. The measurements result in a satisfactory and good matching condition for the dual-band antenna.

Performance of CDMA/TDD in Multimode Scenario for Dual-band Operation (이중대역 동작을 위한 멀티모드 시나리오에서 CDMA/TDD의 성능)

  • Oh, Hyeong-Joo;Hwang, Seung-Hoon
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.45 no.11
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    • pp.32-36
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    • 2008
  • In this paper, we investigate the capacity of CDMA/TDD in the inner zone of multimode scenario with dual-band operation where high frequency band is used for TDD in the inner zone and lower frequency band is utilized for FDD in the outer zone. The effects of various system parameters such as cell radius, date rate, and time slot allocation are analyzed.

WLAN Dual Band Dipole Antenna with Parasitic Elements and Reflector for High Gain Operation (기생 및 반사 소자를 갖는 고 이득 WLAN 이중 대역 다이폴 안테나)

  • Park, Sung-Il;Jung, Jin-Woo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.2
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    • pp.341-348
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    • 2018
  • A WLAN dual band dipole antenna with parasitic elements and a reflector is presented for high gain operation. The parasitic elements are used for practical application and high gain operation of the radiation pattern at the WLAN dual band. The proposed antenna consists of three layers, and has dimensions of $74mm{\times}40 mm{\times}31.4mm$. From the experimental results, the achieved impedance bandwidths were 1035 MHz (2.031-3.066 GHz) and 1119 MHz (5.008-6.127 GHz), respectively. The measured maximum gain at each WLAN band was 6.69 dBi and 7.81 dBi, respectively.

Design of a Dual Band High PAE Power Amplifier using Single FET and CRLH-TL (Single FET와 CRLH 전송선을 이용한 이중대역 고효율 전력증폭기 설계)

  • Kim, Seon-Sook;Seo, Chul-Hun
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.2
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    • pp.56-61
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    • 2010
  • In this paper, high efficient power amplifier with dual band has been realized. Dual band power amplifier have used modify stub matching for single FET, center frequency 2.14GHz and 5.2GHz respectively. The dual-band operation of the CRLH TL is achieved by the frequency offset and the nonlinear phase slope of the CRLH TL for the matching network of the power amplifier. Because the control of the all harmonic components is very difficult m dual-band, we have managed only the second- and third-harmonics to obtain the high efficiency with the CRLH TL in dual-band. Dual-band characteristics in the output has to balance. Two operating frequencies are chosen at 2.14 GHz and 5.2 GHz in this work. The measured results show that the output power of 28.56 dBm and 29 dBm was obtained at 2.14 GHz and 5.2 GHz, respectively. At this point, we have obtained the power-added efficiency (PAE) of 65.824 % and 69.86 % at two operation frequencies, respectively.

Dual-Band Feedforward Linear Power Amplifier Using Equal Group Delay Signal Canceller (동일 군속도 지연 상쇄기를 이용한 이중 대역 Feedforward 선형 전력 증폭기)

  • Choi, Heung-Jae;Jeong, Yong-Chae;Kim, Hong-Gi;Kim, Chul-Dong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.7
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    • pp.839-846
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    • 2007
  • In this paper, the first attempt to design a novel structure of dual-band feedforward linear power amplifier(FFW LPA) was presented. Up to now, primary technical difficulty has been the extension of the conventional signal canceller to the dual-band operation. Therefore, we propose the design technique of the dual-band equal group delayed carrier canceller, the dual-band equal group delayed intermodulation distortion(IMD) canceller and the dual-band FFW LPA. The operation frequency bands of the implemented dual-band FFW LPA are digital cellular($f_0=880$ MHz) and IMT-2000($f_0=2.14$ GHz) band, which are separated about 1.26 GHz. With the high power amplifier of 120 W PEP for commercial base-station application, IMD cancellation loop shows 20.45 dB and 25.04 dB loop suppression at each band of operation for 100 MHz. From the adjacent channel leakage ratio(ACLR) measurement with CDMA IS-95A 4FA and WCDMA 4FA signal, we obtained 16.52 dB improvement at the average output power of 41.5 dBm for digital cellular band, and 18.59 dB improvement at the average output power of 40 dBm for IMT-2000 band simultaneously.

Modified Yagi dipole Antenna for WLAN Dual-band Operation (WLAN 이중 대역 동작을 위한 수정된 야기 다이폴 안테나)

  • Park, Sung-Il;Jung, Jin-Woo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.3
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    • pp.533-538
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    • 2018
  • For WLAN dual-band operation, a modified Yagi dipole antenna is presented. The modified dipole antenna consists of a dipole antenna with open sleeves and parasitic elements. The parasitic elements are used for the practical application of the radiation patterns and high-gain operation at the WLAN dual band. The experimental results showed that the achieved impedance bandwidths were 320 MHz (2.4 to 2.72 GHz) and 640 MHz (5.04 to 5.68 GHz), respectively. The measured maximum gain at the two WLAN bands was 7.74 dBi and 6.93 dBi, respectively.

Matching Element Sensitivity Analysis for the Operation of a Dual-band Power Amplifier with CRLH Transmission Lines

  • Lee, Byeonguk;Kim, Changwook;Park, Youngcheol
    • Journal of IKEEE
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    • v.22 no.4
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    • pp.1050-1055
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    • 2018
  • In this paper, we analyzed the sensitivity of matching elements for the dual-band operation of a power amplifier with composite right/left-handed (CRLH) transmission lines. Metamaterial theory enables CRLH transmission to support arbitrary impedance matching at dual frequencies. In general, at sub-GHz range, the CRLH matching networks are commonly implemented with lumped elements, which are prone to manufacturing distribution. In order to reduce the effect from the distribution of element values in design, we suggest a method to analyze the sensitivity of matching elements from the performance aspect of power amplifiers. Based on the analysis, a 40dBm dual-band power amplifier operating at 0.7GHz and 1.5GHz is designed.

Design of A Dual Band Branch Line Coupler Using a CRLH Transmission Line Structure (CRLH 전송선로 구조를 이용한 이중대역 브랜치 라인 커플러 설계)

  • Park, Min-Woo;Koo, Ja-Kyung;Lim, Jong-Sik;Jeong, Yong-Chae;Ahn, Dal
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.12
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    • pp.2462-2467
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    • 2009
  • This paper proposes a dual band branch line coupler (BLC) using a composite right/left handed (CRLH) transmission line. The existing dual band BLCs with open stubs require hundreds of line impedance for the open stub as the frequency bands approach to each other, so it has been almost impossible to realize them. However in the proposed BLC, a CRLH transmission line replaces the open stub with an extremely high line impedance so that the BLC circuit may be realized even two frequencies are close to each other. As an example, a dual band BLC operating at 1800MHz and 2300MHz (the frequency ratio is 1:1.28) is designed and measured. Open stubs with $560\Omega$ line impedance are replaced by CRLH transmission lines for realizing the dual band BLC. The measured performances prove that the dual band operation is well acceptable and the proposed design method is successful even the ratio between two frequencies is not around two nor more.

Dual-band L-section Impedance Transformer (이중 대역 L형 임피던스 변환기)

  • Park, Myun-Joo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.5
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    • pp.67-71
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    • 2010
  • This paper proposes new dual-band impedance transformers based on the L-section circuit topology. The proposed circuits consist of a transmission line section with a stub line either at the source or at the load end. The dual-band operating conditions are analyzed in detail and simple design equations are derived in terms of the line lengths and impedances for the different circuit topologies and load conditions. The dual-band operation is confirmed through the design, fabrication and measurement in microstrip circuits based on the proposed method.