• Proceedings of the Korean Institute of Communication Sciences Conference
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• 1991.10a
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• pp.119-122
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• 1991

In this paper, a new adaptive IIR notch filter employing all pass filter is proposed. Proposed all pass filter is composed of all pole and all zero sections, each of which utilizes modulation lattice filter [11]. And, adaption algorithm for proposed notch filter is also derived. In addition, the error surface for proposed IIR adaptive notch filter is analyzed. Computer simulation results reveal that the proposed adaptation algorithm works well for low SNR(signal to noise ratio) single and multiple sinusoids. And it is shown that for estimation time varying frequency, the parameter which is related to notch bandwidth is important than any other parameters.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.333-337
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• 2003

In this paper, 5.2 GHz WLAN BPF(Band Pass Filter) using LTCC(Low temperature co-firing ceramic) Multilayer technology was simulated and manufactured. A DGS(Defected Ground structure) resonator with spiral ground pattern is used to shorten resonator size and improve circuit Q factor. And the equivalent circuit of BPF was suggested. The measured result shows good agreement with simulated data. Experimental results show the center frequency of 5.25GHz, the insertion loss of 0.14dB, and the 3-dB bandwidth of 350MHz (6%). The center frequency of BPF is 5.25GHz which is available for wireless LAN.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.418-421
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• 2001

The ceramic filters were developed using technology similar to that of quartz crystal and electro- mechanical filter. However, the key to this development involved the theoretical analysis of vibration modes and material improvements of piezoelectric ceramics. The primary application of ceramic filters has been for consumer-market use. Accordingly, a major emphasis has involved mass production technology, leading to low-priced devices. A typical ceramic filter includes monolithic resonators and capacitors packaged in unique configurations. Nakazawa developed a double-mode resonator as two acoustically coupled single resonators. And he developed 10.7MHz crystal filters using multi-energy trapping mode of thickness shear vibration. He succeeded in realizing a two-pole band pass filter response without external inductance by splitting a dot electrode to creak coupled symmetric and anti- symmetric vibration modes. Accordingly, the simulation for ceramic (inter were important. So that, this paper were investigated the pass frequency of filter on the electrode length and thickness of ceramic.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.2A
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• pp.147-152
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• 2005

In this paper, we have proposed a novel DGS(Defected Ground Structure) resonator and has designed the band -pass filter using the proposed ${\subset}$ stub-I type DGS resonator. This structure has strong advantages that can vary the retune loss at the passband freely and also can easily tune the attenuation pole frequency at the stopband. The bandpass filter can be made more smaller than the existing filters and be used to find the various applications for eliminating the harmonics and spurious mode at IMT-2000 band.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.5
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• pp.319-326
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• 1988

In the presence of unmodeled dynamics, the robustness of adaptive pole assignment control using new pseudo-plant is presented. The pseudo-plant proposed by Donati et al. is modified as the gain of low pass filter can be set from zero to one. This modified pseudo-plant results in the reduction of modeling error. It is shown that not only this approach is insensitive to input frequency but also it improves the conic condition developed by Ortega et al. which is required to assure stability of adaptive control system despite the model-plant mismatch. A simple method to compensate the tracking error due to the use of pseudo-plant is considered.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.676-679
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• 2001

A low-temperature cofired-ceramic (LTCC) multi-layer ceramic (MLC) band-pass filter (BPF) is presented, which has the benefits of low cost and small size. The BPF is designed for a IMT-2000 handset. The computer-aided design technology is also presented. The BPF with an attenuation pole at below the passband has been discussed and realized. The equivalent circuit of the BPF was established by transmission lines and lumped capacitors. The frequency characteristics of the LTCC-MLC BPF is well acceptable for IMT-2000 application.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.1
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• pp.56-60
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• 2002

A low-temperature cofired-ceramic (LTCC) multi-layer ceramic (MLC) band-pass filter (BPF) is presented, which has the benefits of low cost and small size. The BPF is designed for an IMT-2000 handset. The computer-aided design technology is also presented. The BPF with an attenuation pole at below the passband has been discussed and realized. The equivalent circuit of the BPF was established by transmission lines and lumped capacitors. The frequency characteristics of the LTCC-MLC BPF is well acceptable for IMT-2000 application.

• The Journal of the Acoustical Society of Korea
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• v.16 no.3
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• pp.106-113
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• 1997

A 3V CMOS continuous-time fully-balanced integrator for low-voltage analog-digital mixed-mode signal processing is designed in this paper. The basic architecture of the designed fully-balanced integrator is complementary circuit which is composed of NMOS and PMOS transistor. And this complementary circuit can extend transconductance of an integrator. So. the unity gain frequency, pole and zero of integrator are increased by the extended transconductance. The SPICE simulation and small signal analysis results show that the UGF, pole and zero of the integrator is increased larger than those of the compared integrtors. The three-pole active low-pass filter is designed as a application circuit of the fully-balanced integrator, using 0.83V CMOS processing parameter.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.5
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• pp.128-132
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• 2017

In this thesis, a BPF(band-pass filter) at the center frequency of 2.14GHz, and bandwidth of 20MHz is designed and implemented using high Q dielectric resonators with ${\varepsilon}_r=38$. The DR(dielectric resonator) is resonated by $TE_{01{\delta}}$-mode and it has a hole in the center of DR. The BPF consists of 6-poles dielectric resonators and the characteristic of elliptic function is obtained by non-adjacent coupling. It has the average insertion loss of 0.97dB and the return loss over 25dB in its passband. In this thesis, the frequency selectivity is more improved by the coupling characteristics between non-adjacent resonators than that of dielectric resonator filters with a Chebyshev response.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2002.05a
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• pp.523-526
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• 2002

This paper presents the simulation of Au / $Ba_{x}$S $r_{1-x}$ Ti $O_3$(BSTO) / Magnesium oxide (MgO) multi-layered and electrically tunable band-pass filters (BPFs) by using high frequency structure simulator (HFSS). This model is a two-pole microstrip edge coupled filter. The filter was designed fur a center frequency about 5.8 GHz. The tunabillity of the filter is achieved using the nonlinear dc electric-field dependence on the relative dielectric constant of BSTO frroelectric thin film. This work seems very promising for future wireless communication systems....