• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.123-126
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• 2002

A proposed multi-layer ceramic (MLC) chip type band-pass filter (BPF) is presented. The MLC chip BPF has the benefits of low cost and small size. The BPF consists of coulped stripline resonators and coupling capacitors. The BPF is designed to have an attenuation pole at below the passband for a receiver band of IMT-2000 handset. The computer-aided design technology is applied for analysis of the BPF frequency characteristics. The passband and attenuation pole depend the coupling between resonators and coupling capacitance. The frequency characterics of the passband and attenuation pole are analysed with the variance of the coupling between resonators and coupling capacitance. An equivalent circuit and structure of MLC chip BPF are proposed. The frequency characteristics of the BPF is well acceptable for IMT-2000 application.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제16권8호
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• pp.740-743
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• 2003

A multi-layer ceramic (MLC) chip type band-pass filter (BPF) is presented. The MLC chip BPF has the benefits of low cost and small size. The BPF consists of coulped stripline resonators and coupling capacitors. The BPF is designed to have an attenuation pole at below the passband for a receiver band of IMT-2000 handset. The computer-aided design technology is applied for analysis of the BPF frequency characteristics. The passband and attenuation pole depend on the coupling between resonators and coupling capacitance. The frequency characterics of the passband and attenuation pole are analyzed with the variation of the coupling between resonators and coupling capacitance. An equivanlent circuit and structure of MLC chip BPF are proposed. The frequency characteristics of the BPF is well acceptable for IMT-2000 application.

• Journal of electromagnetic engineering and science
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• 제1권2호
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• pp.156-160
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• 2001

Very convenient equivalent circuits fur the design of bandpass filters with an attenuation pole in the lower or upper stopband are provided together with necessary closed-form solutions. The proposed approach gives us much flexibility and simplifies the design of inserting attenuation poles.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제16권4호
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• pp.438-446
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• 2005

In this paper, the modified generalized Chebyshev rational function is presented. The new element values of prototype low pass filter are obtained by network synthesis using this rational function. This proposed filter has an equal ripple passband as same as conventional generalized Chebyshev filter, but unlike conventional filter which has only one attenuation pole at finite frequency, the proposed filter has two different from each other attenuation pole in stopband. If the harmonic frequency is set to the second attenuation pole frequency, this harmonic is suppressed efficiently. Furthermore, since the location of the second attenuation pole can be arbitrary adjusted. our filters are very available for the realization of wide stopband, particularly.

• Journal of electromagnetic engineering and science
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• 제15권2호
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• pp.76-81
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• 2015

This paper presents a design of a transmission line negative group delay (NGD) circuit with multiple pole characteristics. By inserting an additional transmission line into a conventional NGD circuit, the proposed circuit provides further design parameters to obtain wideband group delay (GD) and to help reduce signal attenuation. As a result, the number of gain compensating amplifiers can be reduced, which can contribute to stable operation when integrated into RF systems. The multiple pole characteristics can provide wider NGD bandwidth and can be obtained by connecting resonators with slightly different center frequencies separated by quarter-wavelength transmission lines. For experimental validation, an NGD circuit with two poles GD characteristic is designed, simulated, and measured.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• 제13권7호
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• pp.583-591
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• 2000

It this paper the multilayer chip band pass filter for next generation mobile communication phone is fabricated and designed. For the design the multilayer chip filter of non-contented equivalent circuit and contented equivalent circuit with attenuation pole is presented. Finally it is fabricated and designed using the multilayer chip filter of contented equivalent circuit with attenuation pole. The size insertion loss center frequency and band width of multilayer chip filter are 4.5$\times$3.2$\times$2.0[mm], 3.0[d.B] and 1945$\pm$25 MHz respectively. The multilayer chip filter was fabricated by screen printing with Ag electrode after tape casting. Simulation results of multilayer chip filter are compared with experimental results and found to be in excellent agreements.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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• pp.339-342
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• 1998

A high performance, high-dielectric stripline filter has been developed. The filter consists of planar resonators and its structure is made of high permittivity multilayer ceramic. The performance is distinctive with its attenuation pole. An equivalent lumped circuit is derived to explain the behavior of the attenuation pole quantitatively. A precise design procedure is also described.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제16권11호
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• pp.1155-1163
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• 2005

In this paper, we suggest the new method to considerably enlarge stopband without increment of filter sire and loss. The proposed low pass filter looks like outward configuration with the published Modified Generalized Chebyshev (MGC) low pass filter, but the element values completely differ from each other. The published MGC fille, had been considered only the second attenuation pole to reject(or suppress) the harmonic, whereas the stopband of the proposed filter is superior to the published MGC filter because not only the second attenuation pole but also the third harmonic of the first attenuation pole is made use of profitably. We fabricate a low pass filter according to the proposed theory. From the measurement of the fabricated filter, we can confirm that the stopband of the proposed filter is reached above 4 times wider than the conventional Generalized Chebyshev(GC) filter and above 1.7 times wider than the published MGC filter.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제14권9호
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• pp.924-930
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• 2003

In this paper, a novel miniaturized microstrip duplexer with attenuation pole is proposed. A three-pole microstrip CT(Cascade Trisection) two bandpass filters have each asymmetrically prescribed transmission zero are design and fabrication. This CT bandpass filter changes coupling structure, which not only shifts the location of attenuation poles but also improves skirt characteristics. The duplexer results of measurement with the cross coupling CT bandpass filters has been yielded better isolation and sharper skirt behavior than that with a conventional bandpass filter. The results of measurement are almost similar to those of simulation results.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.751-755
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• 2003

In this paper, We proposed compact multi-layer LTCC (Low Temperature Cofired Ceramic) bandpass filter for Bluetooth module. A ${\lambda}/4$ coupled stripline resonators are designed, which composed of coupled strip-line section and loading capacitance. This resonator with a loading capacitor has slow-wave characteristics. Due to the slow-wave effect of the proposed resonator, it is possible to design and fabricate a compact bandpass filter with a wide upper stop band. Attenuation poles in the lower stop band are achieved using controlling of electro-magnetic coupling between resonators. Using multi-layer LTCC technology, we designed and fabricated band pass filter with a finite attenuation pole and wide upper stopband. The overall size of the filter is $1.2{\times}2.0{\times}1.0mm^3$.