• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.4
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• pp.571-577
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• 1986

In this paper, we have investigated pole-zero shifting due to variable stopband frequency Ws and passband ripple Ap of elliptic function filters. Also we have studied the phase, group-delay, unit step response and impulse response of elliptic filters. We show that in the passband the phase linearity improves as Ws increases, and eventually it approaches that of a chebyshev function filter.

• Journal of electromagnetic engineering and science
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• v.4 no.3
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• pp.102-106
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• 2004

A novel Genetic Algorithm(GA)-based method is suggested to transform a coupling matrix to another, without the procedure of Matrix Rotation. This can remove tedious work like pivoting and deciding rotation angles needed for each of the iterations. The error function for the GA is simply formed and used as part of error minimization for obtaining the solution. An 8th order dual-mode elliptic integral function response filter is taken as an example to validate the present method.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.12
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• pp.45-50
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• 1994

The elliptic filters are optimal in the sense that the magnitude characteristic exhibits the steepest slope at the cutoff frequency. The other characteristics such as delay and step response, however, are rather undesirable. In this paper, the modified elliptic low-pass filter function is proposed. The modified elliptic function possesses progressively diminishing ripples in both passband and stopband, and the lower pole-Q, values when compared to the elliptic counterparts, thus producting the flatter delay characteristics and improved time-domain performances. And it is realizable in the doubley-terminated ladder structures for the order n even or odd, thus lending themselves amaenable to high-quality active RC or switched capacitor filters through the simulation techniques.

• Journal of the Society of Naval Architects of Korea
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• v.41 no.4
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• pp.38-44
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• 2004

The motion response analysis of a submerged elliptic cylinder in waves is presented and the elliptic cylinder is a simplification of the section of submarine in this paper. The method is based on boundary integral method and two-dimensional 3 degree motions are calculated in regular harmonic waves. The fully nonlinear free surface boundary condition is assumed in an numerical domain and this solution is matched along an assumed boundary as a linear solution composed of transient Green function, The large amplitude motions of an elliptic cylinder are directly simulated and effects of wave frequency, wave amplitude and the distance from buoyancy center to gravity center are discussed.

• 한국ITS학회:학술대회논문집
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• 2004.11a
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• pp.306-310
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• 2004

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.9
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• pp.1229-1235
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• 1995

In this paper an elliptic response dual-mode 4-pole bandpass filter was designed, manu-factured, and tested. A dual-mode filter having two stages cascaded double-tuned cavities which are resonant in two independent orthogonal TE113 circular-cavity modes and provide a bandpass response. A 4-pole dual-mode elliptic function bandpass filter has a center frequency of 14.022 GHz with a bandwidth of 36 MHz which is the first channel of the KOREASAT up-link frequency. The measured experimental results of a dual-mode filter are 1 dB insertion loss in the passband and 20 dB out-of-rejection.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.11 no.5
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• pp.315-322
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• 1986

In this paper, we have studied on the IIR digital filters design using Elliptic functions. In process of transformation to digital fouctions from analos Elliptic functions, Bilinear z transformation method has been silized. Designing of digital filter using the Bilinear z transformation the problems of aliasing can be avoidedm whereas the frequency distrotion is generated. The transformation form analog function to digital function is not equal in the region of the cut off frequency response caused by this effect. Avoiding the problem of this effect, we have used proewarping method. Finally, the magnitude characteristics of digital filters are compared with its of analog filters by computer simulation. The results have shown that the magnitude characteristics of digital filters by the prewarping method have made more remarkable improvement than its of analog filters.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.202-204
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• 2006

A new method is presented to design RF filters without the Similarity Transform of their coupling coefficient matrix as circuit parameters which is very tedious due to pivoting and deciding rotation angles needed during the iterations. The transfer function of a filter is directly used for the design and its desired form is derived by the optimized rational-function fitting technique. A 3rd order Coaxial Lowpass filter and an 8th order dual-mode elliptic integral function response filter are taken as an example to validate the proposed method.

• Journal of information and communication convergence engineering
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• v.9 no.3
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• pp.256-259
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• 2011

In this article, new microstrip slow-wave bandpass filters using open loop resonator loaded with inter-digital capacitive fingers is proposed. The filter features not only compact in size, but also exhibits spurious stop-band rejection. Filters of this type with elliptic function and Chebyshev response are demonstrated. There is good agreement between experimental and full-wave electromagnetic (EM) simulation results.

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.185-190
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• 2005

This work presents a numerical procedure to optimize the elliptic-shaped pin fin arrays to enhance turbulent heat transfer. The response surface method is used as an optimization technique with Reynolds-averaged Navier Stokes analysis of flow and heat transfer. Shear stress transport (SST) turbulence model is used as a turbulence closure. Computational results for average heat transfer rate show a reasonable agreement with the experimental data. Four variables including major axis length, minor axis length, pitch and the pin fin length nondimensionalized by duct height are chosen as design variables. The objective function is defined as a linear combination of heat transfer and friction-loss related terms with weighting factor. D-optimal design is used to reduce the data points, and, with only 28 points, reliable response surface is obtained. Optimum shapes of the pin-fin arrays have been obtained in the range from 0.0 to 0.1 of weighting factor.