• Journal of Advanced Navigation Technology
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• v.27 no.1
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• pp.57-62
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• 2023

This paper proposes a tri-band bandpass filter using dual-mode stepped-impedance resonators (SIRs) with parallel coupled structures. The proposed filter adopts U-shaped SIRs with open stubs and parallel coupled lines (PCLs) that have inter-digital and comb-line shorted ends. Two U-shaped SIRs with open stubs build the first and third passband, and the central PCL resonators build the second passband. Five resonators and coupling structures are theoretically analyzed to derive the scattering parameters of the proposed filter. A novel tri-band bandpass filter is designed and fabricated using the induced scattering parameters. The measured result of the fabricated tri-band bandpass filter shows a good agreement with the simulated one.

• ETRI Journal
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• v.36 no.1
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• pp.163-166
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• 2014

A microstrip dual-wideband bandpass filter using a multimode resonator (MMR) is proposed in this letter. The proposed MMR loaded with a T-shaped open-ended stub and a short-ended stub exhibits triple mode characteristics, and a synthesis method is developed to illustrate the wide passband with independently controllable center frequencies and bandwidths. To verify this design methodology, a dual-wideband filter with fractional bandwidths of 19.1% and 27.9% is designed and fabricated. The measured results agree with the simulations.

• ETRI Journal
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• v.30 no.2
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• pp.344-346
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• 2008

In this paper, we present a novel oscillator (OSC) design. Bandpass filters, which can suppress harmonics, are incorporated into a co-design with an OSC to improve the OSC phase noise and harmonic rejection. The proposed OSC/bandpass filter co-design achieves a phase noise of -130.1 dBc/Hz/600 kHz and harmonic rejection of 37.94 dB and 40.85 dB for the second and third harmonics, respectively, as compared to results achieved by the OSC before co-design of -101.6 dBc/Hz/600 kHz and 21.28 dB and 19.68 dB. Good agreement between the measured and simulated results is achieved.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.293-298
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• 1993

In ground vehicles, the increasing demand for safety and ride comfort which are trade-off relation, especially at high speeds, has led to the development od actively controlled suspensions. The LQG/LTR controller can be used to design a robust feedback control system that deals with disturbance rejection properties as well as insensitivity to modelling errors and sensor noise. And when the disturbance can not be measured but is limited within a certain frequency range, a bandpass feedback to eliminate the disturbance response can be used. In this paper, hybrid controller cosisted of bandpass feedback controller and LQG/LTR controller is applied to a quarter-car model moving on a randomly profiled road. The random road profile considered as colored noise is shaped from white noise by use of shaping filter. The performance of the hybrid control system is compared with that of an LQG/LTR controlled system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.11
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• pp.2127-2130
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• 2008

In this paper, a tunable bandpass filter with mutual inductive coupling circuits is newly designed and demonstrated for UHF TV tuner ranged from Ch.14(473MHz) to Ch.69(803MHz) applications. Conventional HF tuning circuit with an electromagnetic bandpass filter has several problems such as large size, high volume and high cost, since the electromagnetic filter is comprised of several passive components and air core inductors to be assembled and controlled manually. To address these obstacles, peaking chip inductor was newly applied for constructing the mutual inductive coupling circuit. The proposed circuit was newly and optimally designed, since the chip inductor showed lower components Q-value than the air core inductor. A varactor diode has been also used to fabricate the proposed tunable bandpass filter for RF tuning circuit. The fabricated tunable filter exhibited low insertion loss of approximately -3dB, high return loss of below -10dB, and large tuning bandwidth of 330MHz.

• Journal of Navigation and Port Research
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• v.35 no.4
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• pp.299-302
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• 2011

In this letter, the effect of quality factor on center frequency deviation in miniaturized coupled line bandpass filter (BPF) with diagonally end-shorted at their opposite sides and lumped capacitors is theoretically analyzed. The miniaturized BPF of a two-stage structure with two types of quality factors in standard CMOS process was designed and manufactured at 5.5 GHz. The die area of BPF was $1.44{\times}0.41\;mm^2$. The measured center frequency of BPF with a quality factor of 4.9 was deviated from 5.5 GHz to 4.7 GHz. The one with 14.8 was shifted to 5GHz. The theoretical and measured results validate that quality factor influences the center frequency shift of BPF.

• Journal of Navigation and Port Research
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• v.34 no.7
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• pp.543-552
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• 2010

Modified compact combline bandpass filters are proposed based on the miniaturized quarter-wave transmission line which is composed of the parallel coupled line and lumped capacitors. The electrical length of the parallel coupled line in a resonator, which determines the size of combline bandpass filters, is just $5^{\circ}$ or $7^{\circ}$, resulting in a compact circuit area. The designed combline bandpass filter also has a wide upper stopband by suppressing the spurious passbands, not moving. Measured results of two fabricated filters centered at 400MHz show good agreement with the theoretical predications.

• Journal of Electrical Engineering and Technology
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• v.8 no.5
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• pp.1152-1156
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• 2013

We propose a compact high-order(9th) UHF bandpass filter comprising the composite right-handed and left-handed(CRLH) zeroth-order resonators(ZORs) in the form of the three cascaded-triplets(CTs) newly applied to the ZOR filter which results in very steep skirt. The method is verified by circuit and EM simulations and measurement with metamaterial properties.

• Nuclear Engineering and Technology
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• v.4 no.3
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• pp.181-185
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• 1972

A digital bandpass filter method is investigated for the data treatment in tile measurement of the reactor transfer function. It was found that the technique is very effective in eliminating the effects of external noise. A computer code was programmed for this method. The frequency response of a digital filter is calculated, and the data treatment with this method using a digital computer was illustrated for triangular and square waveforms. Error and restriction involved in use of this method are discussed.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.237-240
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• 2005

A novel current mode high Q bandpass filter with electronically tuable values of Q based on second generation current controlled conveyor CCCIIs is presented. The circuit offers the advantages of using a few passive elements. The center frequency and pole-Q can be independently adjusted by via dc bias current of CCCIIs, It is shown from SPICE simulation that the results agree well with theoretical analysis