• Title, Summary, Keyword: Bandpass

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A Complex Bandpass Sampling Method for Downconversion of Multiple Bandpass Signals (다중 대역통과 신호의 하향변환을 위한 Complex Bandpass Sampling 기법)

  • Bae, Jung-Hwa;Ha, Won;Park, Jin-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.9C
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    • pp.913-921
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    • 2005
  • A complex bandpass sampling technique can provide a more flexible architecture for designing a software- defined radio(SDR) system, because it has several advantageous features of larger sampling range and lower minimum sampling frequency than a real bandpass sampling method. In spite of the potential advantages of the complex bandpass sampling, solid investigation for the direct downconversion of multiple signals by the complex sampling theory has not been reported yet. Thus, we propose in this paper a novel scheme for the downconversion of multiple signals using the complex bandpass sampling, and develop the formulae related to the complex bandpass sampling for practical usage, such as the valid sampling range, the intermediate frequency (If), and the minimum sampling frequency of the downconversion of multiple RE signals. Such derived formulae are verified from simulations.

Complex Bandpass Sampling Technique and Its Generalized Formulae for SDR System (SDR 시스템을 위한 Complex Bandpass Sampling 기법 및 일반화 공식의 유도)

  • Bae, Jung-Hwa;Ha, Won;Park, Jin-Woo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.7C
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    • pp.687-695
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    • 2005
  • A bandpass sampling technique, which is a method directly downconverting a bandpass signal to a baseband or a low IF signal without analog mixers, can be an alterative choice for the SDR system to minimize the RF front-end. In this paper, a complex bandpass sampling technique for two bandpass-filtered signals is proposed. We derived generalized formulae for the available sampling range, the signal's IF and the minimum sampling frequency taking into consideration the guard-bands for the multiple RE signals. Thru the simulation experiments, the advantages of the . complex bandpass sampling over the pre-reported real bandpass sampling are investigated for applications in the SDR design.

Design of LTCC Bandpass Filter using Multilayer Resonators (적층 구조의 공진기를 이용한 LTCC 대역통과 여파기의 설계)

  • Seong Gyu Je;Yang Seung Hwan
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • pp.234-238
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    • 2003
  • The LTCC bandpass filter using multilayer resonators is made of combline type and interdigital type parallel coupled-lines. The equivalent circuits of parallel coupled-lines are analysed. They are applied to make an equivalent circuit of LTCC bandpass filter using multilayer resonators. The 3-pole bandpass filter of the center frequency of 2.45GHz with 250Hz bandwidth is designed and fabricated. The simulated result of the bandpass filter are presented.

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Equivalent Circuit Design of 2.4GHz Band LTCC Bandpass Filter (2.4GHz 대역 LTCC 대역통과 여파기의 등가회로 설계)

  • 성규제;양승환;김동연;유재하;여동훈
    • Proceedings of the IEEK Conference
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    • pp.313-316
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    • 2003
  • The LTCC bandpass filter using multilayer resonators is made of combline type and interdigital type parallel coupled-lines. The equivalent circuits of parallel coupled-lines are analysed. They are applied to make an equivalent circuit of LTCC bandpass filter using multilayer resonators. The 3-pole bandpass filter of the center frequency of 2.45GHz with 200Hz bandwidth is designed and fabricated. The simulated result of the bandpass filter are presented.

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A Design of Varactor-Tuned Combline Bandpass Filter Using Coupling Varactor Diode

  • Kim Byung-Wook;Back Hyung-Il;Yun Sang-Won
    • Journal of electromagnetic engineering and science
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    • v.5 no.2
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    • pp.80-86
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    • 2005
  • In this paper, a novel varactor-tuned combline bandpass filter is presented. The coupling varactor diode between line elements is introduced to control the passband bandwidth so that the passband bandwidth can be maintained almost constant within the tuning range. The equivalent circuit and design equations are derived, and the optimum design is discussed. A 1.7 GHz, two-pole bandpass filter with a bandwidth of $4.5\%$ was constructed. The absolute passband bandwidth was maintained almost constant within more than 0.4 octave tuning range.

The Design of A 1.9 GHz CMOS RF Bandpass Amplifier (1.9GHz CMOS RF 대역통과 증폭기의 설계)

  • 류재우;주홍일유상
    • Proceedings of the IEEK Conference
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    • pp.1121-1124
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    • 1998
  • A CMOS RF bandpass amplifier which performs both functions of low-noise amplifier and bandpass filter is designed for the application of 1.9 ㎓ RF front-end in wireless receivers. The positive-feedback Q-enhancement technique is used to overcome the low gain and low Q factor of the bandpass amplifier. The designed bandpass amplifier is simulated with HSPICE and fabricated using HYUNDAI $0.8\mu\textrm{m}$ CMOS 2-poly 2-metal full custom process. Under 3 V supply voltage, results of simulation show that the CMOS bandpass amplifier provides the power gain 23dB, noise figure 3.8 dB, and power dissipation 55mW.

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Computer aided design of miniaturized wavegude bandpass filters (소형 도판관 대역통과 여파기의 CAD 설계)

  • 성규제;박정호;윤상원;장익수
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.9
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    • pp.15-20
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    • 1997
  • Waveguide bandpass filters using E-plane or H-plane discontinuities have been used in many satellite communication systems. Since the transmitter and receiver of such systems tend to be getting smaller, components such as bandpass filters must also be reduced in size. In this paper, in order to reduce the waveguide, itself, of which bandpass filters consist, double plane step waveguide discontinuities are considered. They are analyzed using the mode matching method and the genralized scattering parameter of the cascaded structure is calculated. The characteristics of the bandpass filter which is designed using the reduced size waveguide is optimized by OSA90$^{TM}$. The bandpass filter has a good characteristics and smaller size than those made of the E-plane or H-plane step discontinuities.s.

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A Miniaturized CMOS MMIC Bandpass Filter with Stable Center Frequency for 2GHz Application

  • Kang, In Ho;Guan, Xin
    • Journal of Navigation and Port Research
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    • v.36 no.9
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    • pp.737-740
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    • 2012
  • A miniaturized CMOS bandpass filter for a single RF transceiver system is presented, using diagonally end-shorted coupled lines and lumped capacitors. In contrast to conventional miniaturized coupled line filters, it is proven that the effective permittivity variation of the coupled transmission line has no effect on shifting the center frequency when the bandpass filter is highly miniaturized. A bandpass filter at a center frequency of 2 GHz was fabricated by $0.18{\mu}m$ CMOS technology. The insertion loss with the die area of $1500{\mu}m{\times}1000{\mu}m$ is -5.14 dB. Simulated results are well agreed with the easurements. It also verify the center frequency stability in the compact size bandpass filter.

Tunable Bandpass Filter with Varactors Based on the CRLH-TL Metamaterial Structure

  • Kim, Beom Kyu;Lee, Bomson
    • Journal of electromagnetic engineering and science
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    • v.13 no.4
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    • pp.245-250
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    • 2013
  • This paper presents a tunable bandpass filter based on the varactor-loaded composite right- and left-handed transmission line (CRLH-TL). The proposed filter is composed of one CRLH-TL unit cell, which corresponds to the third-order bandpass filter. The tunable bandpass filter is designed using only lumped-elements. The use of lumped elements saves space and lowers the fabrication cost. The size of the proposed tunable bandpass filter is $17mm{\times}5mm$, neglecting the feed lines and DC lines. All of the varactors are controlled by one DC bias. The center frequency of the bandpass filter can be controlled by varying the value of the varactors. The tunable range of the center frequency is from 412.5 to 670 MHz. The insertion loss is less than 3 dB, the return loss is more than 10 dB in the passband.

An RF Amplitude Equalizer ; Improved Passband Flatness of a Bandpass Filter

  • Hwang, Hee-Yong;Jung, Jung-Seong;Yun, Sang-won
    • Journal of electromagnetic engineering and science
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    • v.1 no.1
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    • pp.83-87
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    • 2001
  • Many communication systems require bandpass filters with sharp skirt frequency characteristics in order to avoid the interferencce, which results in more order in the filter design. However, because of the limited Q values bandpass filters made of small sized ceramic resonators suffer from relatively large ripples at the band edges as the order of the filter increases. In order to compensate the large ripples while maintaining the sharp skirt frequency we propose a new RF amplitude equalizer. The equalizer made of two pole bandpass filter and an amplifier whose amplitude characteristics are the reverse of those of the bandapss filter. At the cellular band 9-pole bandpass filter with 10 MHz bandwidth exhibits 3 dB ripple when 8mm*8mm ceramic coaxial resonators are used. We added the RF equalizer to this filter and the flatness is improved as less than 1 dB.

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