• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.169-171
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• 2001

본 논문에서는 유한요소법에 기초한 상용프로그램을 이용하여 도파관 필터를 시뮬레이션을 할 경우 도체에 의한 손실을 포함시키는 방법을 제시하였다. 우선 균일한 도파관의 도체에 의한 감쇠의 시뮬레이션 결과를 이론치와 비교하였다. 다음으로 도파관 대역통과 필터의 통과대역 감쇠의 측정결과와 시뮬레이션의 결과를 비교하여 시뮬레이션의 정확도를 검증하였다.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.5
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• pp.927-932
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• 2024

In this paper, the waveguide filter is realized by using the 3D printing and electroplating process. The waveguide filter is consisted of the resonator and the inductive window. The resonator is made small by putting vertical pillar inside the cavity. In case of in/output, the pin of SMA connector is connected to the pillar using the tapped-line method. Designed filter has the volume of 24.0 x 58.0 x 38.0 mm3 that is about 91% reduced compared to general cavity filter. Designed filter is modeled divided into upper part that has the inductive window and lower part that has the pillar. Printed filter by the ABS plastic is plated with 10㎛ thick copper over nickel electrodes. Fabricated filter is measured with the center frequency of 2.397GHz and bandwidth of 4.76%. Also, the insertion loss of filter has 0.15dB and return loss is shown under the 20dB. Suggested waveguide filter with pillar and manufacturing process allows the waveguide devices to be made small, lightweight, and low-cost and can be applied to various RF system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6A
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• pp.818-824
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• 2000

For the purpose of improving the stopband characteristics, the filter structure having single or double inserted metal plates in the waveguide of a reduced width have been widely stdudied so far. Usually such structures have a waveguide junction discontinuity between two waveguides of different widths. In designing such structures, we should always minimize the insertion loss due to the juction discontinuity. Besides it is difficult to fabricate the junction with desired accuracy. Here we consider new structure of tripple metal insert filter without the junction discontinuity problem, which is more suitable for mass production. An optimization procedure is taken with manufacturing error 0.1mm of inserted metal length. The theory agrees well with experimental data. so, it is show that fabrication of triple metal insert filter is more profitabel by optimization process.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.5
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• pp.965-970
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• 2018

In this paper, the transition of the folded substrate integrated waveguide (FSIW) using two substrates is suggested and applied to the bandpass filter. The FSIW has similar characteristics with the SIW and can be reduced the width of the SIW. The transition between the FSIW to the microstrip is designed by using shorted quarter wavelength line. Also, the bandpass filter is designed by using the FSIW and the elliptic lowpass filter of 5 section. Fabricated bandpass filter has the center frequency of 5.75 GHz and the bandwidth of 33.2%. Also, the insertion loss and return loss at the center frequency are 0.63dB and 19.1dB, respectively.

• Journal of Broadcast Engineering
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• v.3 no.1
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• pp.93-99
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• 1998

본 논문에서는 Ka-밴드 위성통신 송신주파수대역(30.085∼30.885 GHz)의 대역통과 필터를 유도성 fin-line 구조를 이용하여 분석, 설계 및 제작하였다. 도파관내의 공진기들이 전계면에 수직한 금속 fin으로 구성된 구조를 해석하는데 가장 적합한 모드정합법을 사용하여 설계하였다. 제작된 필터는 마이크로파대역 뿐만 아니라 밀리미터파대역의 주파수에서도 우수한 필터특성을 갖는다는 특징을 가지고 있으며, 상업용 도파관을 사용하는 대신에 가격이 저렴하고 가공이 용이한 알루미늄을 사용함으로써 대량생산이 가능하다. 또한 도파관내 금속삽입형태에 의한 대역 통과 필터의 구현이 아닌 유한한 두께를 갖는 포토-에칭된 유전체 기판을 삽입함으로써 제작성의 어려움을 해결하였다. 설계, 제작된 필터의 측정결과 통과대역내에서 1.6dBal만의 삽입손실과 18dB이상의 반사손실을 갖는 응답특성을 얻었으며 이론에 의한 계산치와 측정치와의 비교를 통해 본 논문에서 제안된 설계방법의 타당성을 입증하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.5
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• pp.515-524
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• 2013

The program for dielectric ceramic waveguide filter was developed based on the direct coupled filter of ${\lambda}/2$ step impedance prototype. This developed program was called DWFD(Direct coupled Waveguide Filter Design). The filter was designed by 3-dimensional laminated type to reduce the size at the 1 GHz. S scattering matrix for this filter was calculated using the DWFD program. The width of inductive irises for laminated filter was computed by HFSS simulation tool. This waveguide filter was designed by 8 poles with bandwidth 25 MHz at the center frequency 881.5 MHz. By using a dielectric constant 35.4 and laminated type, the size of filter was reduced with width 50 mm and height 48 mm rapidly. We can see that the measured results agree well with the HFSS simulation result. Finally, this paper is shown that the design and implementation of waveguide filters can be presented by using DWFD program simply.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.648-651
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• 2009

Using a mode-matching technique, a waveguide structure with multiple stubs which is utilized as the component of various communication systems has frequency filtering characteristics. We define a proper fitness function to automatically design the pass and stop bands of a waveguide structure with multiple stubs for frequency filtering and the genetic algorithm can be implemented with the fitness function proposed in this paper. The frequency filtering characteristics are numerically computed and parametric sweeps are also performed.

• Proceedings of the Korea Contents Association Conference
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• 2008.05a
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• pp.543-546
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• 2008

A genetic algorithm is introduced to design a waveguide filter which is one of essential elements of satellite system. The waveguide filter composed of waveguide steps is analyzed based on the Green's function and mode-matching technique. Genetic optimization for a waveguide filter is performed in terms of each parameter. Insertion loss behaviors versus frequency are computed and compared with measurement results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.1
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• pp.73-80
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• 2004

In this paper, the implementation and embedding method of the existing air-filled waveguide-filters at millimeter-wave on general PCB substrate is introduced by systematically inserting the vias inside waveguide and mathematically manipulating the simple equations obtained ken the classical circular-post waveguide filter design. All the metal structures placed vertically such as side wall fur perfect ground plane and circular-post for signal control in the air-filled WR-22 waveguide are replaced with several types of via for constructing the bandpass-filter. Side wall and poles inside waveguide are realized by placing a series array of via and tuning the via diameter. The lengths of x, y, z axis are reduced in proportion to root square of employed substrate dielectric constant and especially the length of z axis can be more reduced due to the characteristics of the wave propagation. Because the mass production on PCB is possible without fabricating a large-scaled metal waveguide of WR-22 as input/output ports at millimeter-wave regime, the manufacturing cost is reduced considerably. Finally, when using multilayer process like LTCC for small-sized module, it is one of advantages to use only one layer f3r the filter fabrication. To evaluate the validity of this novel technique, order-3 Chebyshev BPF(Bandpass-Filter) centered at 40 GHz-band with a 2.5 ％ FBW (Fractional Bandwidth) were used. The employed substrate has relative dielectric constant of 2.2 and thickness of 10 mil of Rogers RT/Duroid 5880. Accroding to design and measurement results, a good performance of insertion loss of 2 ㏈ and return loss of -30 ㏈ is achieved at full input/output ports.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.4
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• pp.530-538
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• 1999

In this paper, design of rectangular iris waveguide filter for the microwave broadcasting transponder using WR137 is applied to the modified ${TE^x}_{mn}$ mode theory in order to exactly analyze the characteristic of the waveguide discontinuity. We designed and fabricated the rectangular iris waveguide filter with the bandwidth 47 MHz for the microwave broadcasting transponder applied the conjugate gradient method to the modified ${TE^x}_{mn}$ mode theory. The results show a good characteristics that the $S_{11}$ and $S_{21}$ are -23 ㏈, -0.56 ㏈ and the maximum VSWR is below 1.02 in the passband.