• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.11
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• pp.1700-1705
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• 2012

This study is focusing on ripple elimination in the band pass filter. There are generally two design methods in IIR filter design, which are a direct method and an indirect one. The indirect design method that designs the digital IIR LPF using the prototype analog LPF is applied to this study. A Butterworth filter and a Chebyshev filter are the typical prototype analog LPFs. This study shows characteristics of the digital IIR LPFs that are transformed from the prototype analog LPFs. The designed Butterworth and Chebyshev IIR LPFs are also designed as the band pass filters by frequency transformation in order to compare with the proposed cascading Chebyshev BPFs. This study shows frequency characteristics between the transformed IIR BPFs and the proposed cascading Chebyshev BPFs as well. The proposed cascading Chebyshev BPF is designed by cascading the different orders of Chebyshev BPFs. The aspect of the cascading filter is offsetting the ripples to descend them while the pass band ripples of the Chebyshev filter are ascending and vice versa. The designed cascading Chebyshev filter shows the flatness and the sharpness, which represent the advantages of Butterworth filter in the pass band and of Chebyshev filter in the transition band respectively. This result verifies the validity of the designed filter.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.12
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• pp.1758-1763
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• 2013

This paper is a study on the performance of the stable cascading BPF. There are generally two methods of designing IIR filter, which are a direct method and an indirect one. The indirect design method that is transformed into the BPF by frequency transformation using the prototype analog LPF which is satisfied for designing specifications is applied to this study. As typical prototype analog LPFs, there are the Butterworth filter, the Chebyshev filter and the elliptic filter. In this study, we connect the frequency transformed BPFs (to the cascade form) which have been converted from the stable Butterworth filter and Chebyshev filter. Three classified simulations are conducted in this study, which are the cascading Butterworth BPF Only, the cascading Chebyshev BPF Only and the cascading Butterworth and Chebyshev BPFs. As a result of the simulation, this study shows that a ripple size of the cascading Chebyshev BPF Only is about 1[dB] smaller than that of the cascading Butterworth and Chebyshev BPFs and also the skirt characteristic of the cascading Chebyshev BPF in the transition band is most outstanding and has the widest bandwidth. The result of performance comparison shows the validity of specifications required in the workplace.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.4
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• pp.598-604
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• 2015

A Chebyshev filter is well known for having a sharp skirt characteristic and equi-ripple. On the other hand, a Butterworth filter has a smooth skirt characteristic and maximally flat ripple. This paper analyzes the skirt characteristics of the filters with the cascade connection. The paper deals with the Chebyshev BPF, Cascading Chebyshev BPF, Butterworth BPF, Cascading Butterworth*Chebyshev BPF. First of all, the paper designs the prototype analog LPF in order to analyze skirt characteristics of the BPFs. Then the paper does the frequency transformation into the BPFs and tests the BPFs with cascading them. As a result, the skirt characteristics of the Chebyshev BPF was the sharpest and those of the Cascading Chebyshev BPF, Butterworth BPF, Cascading Butterworth*Chebyshev BPF was superior in order. The validity of the paper was confirmed through minute measurements of test results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.1
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• pp.168-172
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• 2012

This paper is focusing on the comparison of different kinds of BPFs(Band Pass Filters) passing signals with a particular frequency band. According to the different classifications, features and target application systems, BPF has many types. Chebyshev filter which has a steep slope and a few ripples, and Butterworth filter which has no ripple but gentle slope are the most typical BPFs. The ideal filter is flat in the passband and the slope in the transition band is perpendicular. In this paper, we suggest the cascading Chebyshev BPF with the advantages of the Chebyshev filter and the Butterworth filter simultaneously to make a closest filter to an ideal filter. The proposing BPF is the tenth Chebyshev BPF cascading the fourth and the sixth, and it is designed as the tenth cascading Chebyshev BPF. To measure the performance of the designing filter, we have compared and analyzed the tenth Chebyshev filter with the tenth Butterworth filter. As a result, the tenth cascading Chebyshev BPF has decreased the ripple more than 1/4 [dB] in the passband. Finally, the output of the simulation showed the validity of the proposing cascading Chebyshev filter.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.2
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• pp.255-260
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• 2018

This study is focusing on the trade-offs between the passband ripples and transition bands of the Chebyshev BPF, which is converted by using the Chebyshev LPF that is well known as a proto-type analog filter. It is also focusing on the trade-offs between the passband ripples and transition bands of the cascading Chebyshev BPF, as well as, the trade-offs between the two BPFs. The study finds the frequency responses of the proto-type analog LPF, the Chebyshev BPF and the cascading Chebyshev BPF. The study shows the results as comparative analysis tables. The study designs the 10th Chebyshev BPF in order to analyze it easily. The simulation results show that the Chebyshev BPF decreases about 55% of the transition band for the -2.5[dB] passband ripple comparing to the -0.5[dB] passband ripple. This study shows the effectiveness and economic feasibility in the restricted frequency communication environment for the decrease of the transition band as providing the passband ripple margin.

• International Journal of Contents
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• v.11 no.3
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• pp.34-38
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• 2015

A band stop filter is proposed with cascading unit cells that are based on a dual composite right/left-handed (D-CRLH) conductorbacked coplanar waveguide. The parameters of the unit cell have been analyzed to confirm the behavior of each component for the equivalent circuit of the cell. We simulated the dispersion characteristics and energy distribution and have determined that the unit cell has a D-CRLH property. The band stop filter was implemented by symmetrically cascading two of the proposed unit cells. The experimental results for the band stop filter revealed a band rejection performance of 32 dB and a return loss of 0.35 dB in the stopband frequency range from 869MHz to 954MHz. Finally, we show that there is a good agreement in the experimental results and those obtained through the simulations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.13 no.4
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• pp.322-331
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• 1988

In this thesis, an active RC filter using high order inverse chebyshev function is designed and the design method for cascading blocks with low sensitivity and maximum dynamic range is discussed. To have maximum dynamic range, we have proposed the simple algorithm with a pole-zero pairing, the cascading sequence by flatness matrix and optimum gain distribution for a given transfer function. And 2nd order Block is designed with negative feedback to improve the sensitivity problem which had a defect at active RC circuits. Using the suggested method, we have designed the active RC low pass filter of the normalized 7th order inverse chebyshev function, as a results, we have shown that this accord with the given specification.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.8
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• pp.20-30
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• 1994

The lossless bounded real(LBR) two-pair cascade structure is one of the exiting low-sensitivity digital filter structures such as wave digital filters(WDFs) orthogonal filters. They are known to have the same structures which are composed of canonic building blocks interconnected to each other. The LBR two-pair cascade filters amount to describing in a unified manner the existing canonic low-sensitivity filters in terms of transfer matrices and chain matrices. However the existing structures have somewhat degraded low-sensitivity performance because they include dependent parameters within their structures. In this paper we propose a filter structure called “two-type-interlaced(TTI) structure.” eliminating such problem completely. This structures can be viewed as the WDFs of analog ladder circuits. As ladder circuits are obtained by cascading Brune sections and merging neighboring inductors or capacitors. so TTI structures at e obtained by cascading Type 3 LBR two-pairs and merging neighboring Type 1 LBR two-pairs. Next, a test procedure called “LBR test” is also presented in this paper. which determines whether of not the quantized TTI structure is stable . If it is unstable we can fine-tune the quantized parameters to make the overall structure stable. Therefore we can solve the dependent parameter problem completely with TTI structure along with LBR test. test.

• Journal of Electrical Engineering and Technology
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• v.11 no.2
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• pp.463-469
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• 2016

In this paper, the use of a dual composite right/left-handed coplanar waveguide (CPW) transmission line is proposed for the design of a band rejection filter. The notch property of the filter is achieved by combining the convex signal line with the shorted concave meander line, and the equivalent circuit model is extracted from the geometry of the unit cell for organizing the band rejection property. Then the equivalent parameters of the unit cell are analyzed to identify those behaviors. And the dispersion characteristics and energy distributions are simulated. In the end, the band rejection filter is manufactured by cascading two proposed unit cells. We show that the measurement result for the resonant frequency demonstrates good agreement with the simulation result and the band rejection filter provides a rejection performance of 17.5 dB at the stopband frequency ranging from 869 MHz to 894 MHz.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.22 no.7
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• pp.1385-1393
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• 1997

In this paper, a systematic design method of brjoadband tunable bandpass filter is presented by using user defined varactor diode method. The tunable bandpass filter is constructed as the cascade connection of low pass filter and high pass filter. The designed filter shows the characteristeristics of 2.7.+-.0.2dB insertion loss and 37.1.+-.5.0dB insertion loss and 32.1.+-.2.2dB image rejection. The results of the research can be used fodr the broadband tunable filter of DBS tuner and communication instruments.