• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.7 s.98
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• pp.732-739
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• 2005

In this paper, the design and implementation of the Ka-band(20/30 GHz) waveguide diplexer with an E-plane T-junction are described. The waveguide diplexer consists of a transmit filter and a receive filter combined to the antenna port via an E-plane T-junction. The reason why the E-plane T-junction structure was selected is to reduce PIM(Passive Intermodulation) level as the split-plane is located in the low electrical current zone. The optimization was performed using the equivalent circuit so that the computation time might reduce. The structure of the diplexer was designed to handle high power and the multipaction analysis was performed. The multipaction margin was greater than 12 dB and satisfied with ESA/ESTEC recommendation. The manufactured diplexer shows minimum return loss of 22 dB, maximum insertion loss of 0.20 dB and maximum isolation of -40 dB for both transmitted receive bands. Those mean the analysis results of the waveguide diplexer were well agreed with the electrical performance test.

• Proceedings of the Korea Contents Association Conference
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• 2003.11a
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• pp.249-252
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• 2003

Scattering solutions of an H-plane T-junction in a parallel-plate waveguide are theoretically investigated. The iterative procedure and Green's function relation are used to obtain the iterative equations for the $E_{z}$ field modal coefficients, thus resulting in matrix solutions. The scattering characteristics of reflection and transmission powers are presented and compared with other existing results.s.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.30A no.4
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• pp.1-10
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• 1993

This paper presents the designing/manufacturing scheme of the diplexer for satellite transponder which is composed of 2-channel bandpass filters, coupled with E-plane T-junction, having symmetrical waveguide E-plane step discontinuity structures. The 2-channel bandpass filters of the diplexer are designed by the scheme of connecting ${\lambda}_{g}$/2 shunt stub to the waveguide E-plane, playing the role of heat sinks without attaching a special heat sinks and to give the profitable productivity and allow the low-cost manufacturing at mass production, tuning screws are eliminated which have been used to compensate the operating characteristics of manufactured filters. The 2 channel bandpass filters of manufactured 14/12 GHz diplexer for domestic Ku-band satellite transponder have the return loss of 25 dB, insertion loss of 0.3 dB in passband, and below-50 dB of stopband characteristics (T$_{x}$ : f$_{o}{\pm}$250 MHz, R$_{x}$ : f$_{o}{\pm}$220 MHz) at room temperature.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.3
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• pp.335-342
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• 2012

A high-isolation Ka-band WR-28 waveguide power combiner is designed and implemented using a resistive septum. The waveguide power combiner developed here is an E-plane T-junction type with a TaN resistive septum inserted in a slit of waveguide junction. The fabricated waveguide power combiner shows a return loss better than -20 dB and an insertion loss less than 0.1 dB. Also the measurement shows isolation levels of 20 dB or more almost all over the band and in particular 25 dB or more below 37 GHz. The amplitude and phase imbalance are measured to be less than 0.1 dB and $2.5^{\circ}$, respectively.

• Progress in Superconductivity
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• v.3 no.1
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• pp.87-90
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• 2001

We designed a high temperature superconducting rapid single flux quantum(RSFQ) T flip-flop(TFF) circuit using Xic and WRspice. According to the optimized circuit parameters, we fabricated the TFF circuit with $Y_1$$Ba_2$Cu$_3$$O_{7-x}$(YBCO) interface-controlled Josephson junctions. The whole circuit was comprised of five epitaxial layers including YBCO ground plane. The interface-controlled Josephson junction was fabricated with natural junction barrier that was formed by interface-treatment process. In addition, we report second design for a new flip-flop without ground palne.e.

• Proceedings of the Korea Contents Association Conference
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• 2003.05a
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• pp.403-405
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• 2003

An iterative Green's function method (IGFM) is introduced to analyze complex electromagnetic waveguide structures in view of the university student. The IGFM utilizes the Green's function and iteration scheme. The physical mechanism with simple mathematical equations is used to formulate the IGFM. Scattering characteristics of a standard E-plane T-junction in a parallel-plate waveguide are theoretically investigated in terms of the IGFM. Numerical computations illustrate the characteristics of resection and transmission powers versus frequency. A dominant-mode solution is presented and compared with the higher-mode solutions.

• The Journal of the Korea Contents Association
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• v.7 no.2
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• pp.125-131
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• 2007

An iterative Green's function method (IGFM) is introduced in order to analyze complex electromagnetic waveguide stub structures in view of a university student. The IGFM utilizes a Green's function approach and an regional iteration scheme. A physical iteration mechanism with simple mathematical equations facilitates clear formulations of the IGFM. Scattering characteristics of a standard E-plane T-junction stub in a parallel-plate waveguide are theoretically investigated in terms of the IGFM. Numerical computations illustrate the characteristics of reflection and transmission powers versus frequency.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.6
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• pp.787-798
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• 1995

We implement the E-plane T-juncition manifold mutiplexer having low insertion loss for output multiplexer of Ku-band satellite transponder. Manifold multiplexer implemented here is composed of 2 channel filters, T-junctions, half-wave waveguide connecting channel filters and manifold, and manifold itself.[1-4] Considering the mass and volume of the satellite transponder, the channel filters are designed to dual-mode.[5-13] And Elliptic filter function is used, which has good characteristics of suppressing the interference between 2 channels. Since the performance of manifold multiplexer depends on the manifold waveguide transmission line length, it's necessary proper analysis. In this paper, we do optimization process of T-junction and other elements by using CAD and implement the manifold multiplexer. An experiment shows that characteristic response of multiplexer matches wel its modeling result.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.4
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• pp.582-593
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• 1999

This paper presents the design and fabrication of the diplexer for a KOREASAT-III Ka-band satellite transponder. The transmission characteristics of the diplexer is analyzed by calculating the generalized scattering matrix using mode matching method. It is composed of 2 bandpass filters, coupled with H-plane T-junction having symmetrical inductive iris and E-plane metal insert structures. Compared with the size and weight of the Rx and Tx filter loaded with a transponders respectively, those of the diplexer can be effectively reduced. In a high power transmission, the variation of the filter characteristics is minimized by the scheme that irises are extended to the exterior of H-plane of the waveguide. This scheme needs no extra heat sinks for dissipating high power. The diplexer is designed to improve the simplification, durability and reliability by eliminating tuning screws, which have been used to compensate for the characteristics of fabricated filters. The bandpass filters of the diplexer show the insertion loss of less than 1.2 dB and the return loss in excess of 15 dB. The isolations of more than 65 dB have been achieved between Rx and Tx filter.

• Imaging Science in Dentistry
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• v.49 no.1
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• pp.9-17
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• 2019

Purpose: This study aimed to introduce a novel method to evaluate the alveolar bone and interdental septum in the anterior mandible using cone-beam computed tomography (CBCT). Materials and Methods: Fifty-six CBCT scans from adult patients were selected. The CBCT scans were obtained before and after orthodontic treatment. The following measurements were taken: width of the alveolar bone and the interdental septum, height of the interdental septum, height of the bone plates, distance between the cementoenamel junction and marginal bone crests, and vertical positioning of the mandibular incisor, using the lingual plane as a reference. To test the reproducibility and the stability of the lingual plane, a triangle was traced in the anterior mandible. The intra-class correlation coefficient(ICC) was used to determine intra- and inter-examiner agreement. The paired Student t-test was used to evaluate the area of the triangle and the reproducibility of all measurements. Results: The ICC was excellent for the alveolar bone and dental measurements (0.9989 and 0.9977, respectively), as well as for the interdental septum (0.9987 and 0.9961, respectively). The area of the triangles showed stability in the lingual plane (P>0.05). For the alveolar bone, mandibular incisor, and interdental septum measurements, no statistically significant differences were found between the 2 examiners(P>0.05), confirming the technical reliability of the measurements. Conclusion: The method used in this study provides a valid and reproducible assessment of alveolar bone dimensions in the anterior mandible measured on CBCT images.