• Journal of electromagnetic engineering and science
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• v.14 no.4
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• pp.387-392
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• 2014

In this paper, a size-reduced Wilkinson balun with wide harmonic-suppressed band is presented. An accurate analysis of the parallel coupled line with an open stub (PCL-OS) is carried out. The PCL-OS structure shows excellent low pass filter and harmonic-suppression characteristics, which is useful for designing a low pass filter unit cell (LUC) with a reduced size. The designed Wilkinson balun at a 2.45 GHz center frequency not only shows an excellent harmonic suppression including the 5th harmonics up to 14 GHz over 15 dB, but it also has an area reduced to 48% of the conventional one.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.1019-1025
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• 2016

This paper proposes a parallel reduced-order square-root unscented Kalman filter for state estimation of a sensorless permanent-magnet synchronous motor. The appearance of an unscented Kalman filter is caused by the linearization process error between a real system and classical Kalman model. The unscented transformation can make a more accurate Kalman model. However, the complexity is its main drawback. This paper investigates the design and implementation of the proposed filter with Potter and Carlson square-root form. The proposed parallel reduced-order square-root unscented Kalman filter reduces memory and code size, and improves numerical computation. And the performance is not significantly different from the unscented Kalman filter. The experimentation is performed for the verification of the proposed filter.

• Journal of the Semiconductor & Display Technology
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• v.3 no.4
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• pp.45-49
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• 2004

We examined large particles and filter size effects of Central Chemical Supplying (CCS) system for STI-CMP on Light Point Defects (LPDs) after polishing. As manufacturing process recently gets thinner below 0.1 um line width, it is very important to keep down post-CMP micro-scratch and LPDs in case of STI-CMP. Therefore, we must control the size distribution of large particles in a slurry. With optimization of final filter size, CCS system is one of the solutions for this issue. The oxide and nitride CMP tests were accomplished using nano-ceria slurries made by ourselves. The number of large particles in a slurry and the number of LPDs on the wafer surface after CMP were reduced with decrease of the final filter size. Oxide removal rates slightly changed according to the final filter size, showing the good performance of self-made nano ceria slurries.

• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.77-81
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• 2021

In this paper, a low-csst ECG system using a digital filter was implemented. After amplifying the analog ECG signal, it is converted into a digital signal and filtered. The developed ECG module is miniaturized by removing the analog filter element that occupies the existing volume and replacing it with a digital filter using a 3-stage Butterworth filter which is one of IIR filters. It uses a serial monitoring program with C# to check and save the ECG waveform measured on a computer screen. The ECG system using a developed digital filter in this paper uses a low-cost processor instead of an expensive, high-end processor, and its size and price are reduced by converting the analog filter to a digital filter. In addition, since the waveform of the developed ECG system is similar to the actual ECG waveform of MIT-BIU, it is considered that the existing analog filter can be replaced with the developed digital filter.

• Journal of electromagnetic engineering and science
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• v.8 no.1
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• pp.12-16
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• 2008

In this paper, we introduce a coupling, which is achieved through the aperture instead of the conventional edge coupling, so that the bandpass filter is reduced less than half in size compared to conventional planar type. The resulting filter configuration has a near two-fold symmetry, where the aperture coupling is used in the middle of the coupling stages. We designed a bandpass filter using two tapped hairpin resonators, of which the order becomes four. The designed bandpass filter has the size of $8.9{\times}18.3\;mm$. It has the return loss better than 17dB and the insertion loss of less than 5 dB in overall passband. The measured results show good agreements with simulated ones.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.163-166
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• 2005

Multilayer LTCC technology enables RF modules to be reduced dramatically by taking advantage of the three dimension flexibility. Compared to a conventional two dimensional PCB, LTCC allows higher density, reduced size, and lower cost. In this research, BPF based on LTCC for 900MHz ZigBee application was implemented which can replace SAW filter with using the material of the Dupont9599's dielectric constant 7.8. And distributed baud pass filter for 900MHz ZigBee system applications is presented. Using resonator stripline and capacitance, 2nd order band pass filter was designed. Adjusting resonator's length and capacitance is easy to tune at accurate center frequency by shifting band because ZigBee system is using narrow bandwidth, $902MHz^{\sim}928MHz$. Also resonator has no limitation in space, so reducing size is possibile. Designed filter had I.L. 2.8dB at 915MHz and attenuation at 815MHz, 1015MHz was 16dB, 15dB, respectively. Therefore, the sharpe cut-off and good insertion loss for ZigBee system application.

• ETRI Journal
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• v.28 no.5
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• pp.607-614
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• 2006

This paper presents a new class of microstrip slow-wave open-loop resonator filters with reduced size and improved stopband characteristics. A comprehensive treatment of both ends loaded with triangular and rectangular ends is described, leading to the invention of a microstrip slow-wave open-loop resonator. Two-resonator and four-resonator bandpass filters are designed at the operating frequency of about 2 GHz, and a bandwidth of 60 MHz. The size of the slow-wave open-loop resonator is optimized from the standpoint of the unloaded Q-factor. The filters are not only compact in size due to the slow-wave effect, but also have a wider upper stopband resulting from the dispersion effect. The filter designs of this type are described in details. The experimental results are demonstrated and discussed.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.4
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• pp.217-222
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• 2006

A distributed balun such as Marchand balun typically shows good phase and amplitude balances, but its size is somewhat large especially in lower frequency band. In contrast, a lumped balun has compact size but its performance is not good compared with that of a distributed one. In this paper the distributed-coupled line can be reduced effectively by using the lumped-distributed implementation. Designed balun has two coupled line of each ${\lambda}/72$ and shows magnitude balance of 0.05 dB, phase balance of $0.7^{\circ}$ in passband. Balanced-type filter is designed using balun and it has insertion loss of 8 dB, return loss of 7 dB, magnitude balance of 0.2 dB, and phase balance of $1.2^{\circ}$ in passband.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.4
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• pp.487-493
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• 2001

In this paper, A new microstrip bandpass filter is proposed. The novelty of the proposed structures is to use a interdigital capacitor and embeded slot that are fanned on a patch resonator such that its insertion loss and size can be significantly reduced simultaneously. As a result, it is found that the resonant frequency of patch filter designed at 5 GHz is decreased to 1.8946 GHz and the insertion loss is reduced from -2.168 dB to -0.379 dB. This proposed filter has small size and low insertion loss in comparison with the conventional parallel edge coupled bandpass filter.

• 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.