• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.13 no.6
• /
• pp.582-589
• /
• 2002

This paper presents 12.2 GHz ~ 12.7 GHz frequency band reflection type 5-bit digital phase shifter with constant insertion loss property that was fabricated with relatively low cost's InGaAs HEMT for amplifier. The unavoidable large insertion loss difference between on and off states of HEMT, when it is designed by conventional design theory based on ideal switching device, is removed by transforming the HEMT impedances at on and off states to other proper values connecting a certain length transmission line to HEMT and then applying the conventional design theory. The fabricated 5-bit digital phase shifter shows very good insertion loss properties of less than 1.5 dB insertion loss difference and -4.5 dB ~ -6 dB insertion loss in 35 phase steps at 12.2 GHz ~ 12.7 GHz. These results verify the design method presented in this paper, which is useful to design phase shifter of constant insertion loss with non-ideal switching device.

• The Journal of the Acoustical Society of Korea
• /
• v.21 no.7
• /
• pp.624-631
• /
• 2002

The insertion loss of the noise barriers with several top shape is measured in an anechoic room by using a reduced scale model test. The insertion loss differences between a straight vertical barrier having 0.3 m height and several barriers with simple top shaped are compared. The results show that the latter is more effective than the former and absorptive barrier is more effective than the reflective one. Among the barrier types of 'T', 'Y', and '(equation omitted)', type 'Y' is the best one and the rest have similar effect. This result is well agree with Alfredson (PIOC. Inter-Noise 95, p. 381, 1995)'s but contradict to May (J. Sound Vb. 71, p. 73, 1980)'s. Therefore, it is difficult to determine which type is the best. In order to find out this discrepancy, boundary element method is adopted and the result shows one can have different result because each supposed different experimental conditions like height of noise barrier, positions of sound source and receiver, etc.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.22 no.7
• /
• pp.675-682
• /
• 2011

This paper presents two ground plane effects due to the size of two rectangular apertures for two-wire transmission line with equal line length crossing the changeable rectangular apertures in infinite ground planes. The CST MWS is used to determine the characteristics of the insertion loss of the transmission line from the load section in accordance with the ground plane aperture size. The results show that the insertion gain and the insertion loss are periodically observed for the multiple frequency of the half wavelength resonance by the wire length when the transmission line is nearby to horizontal side or vertical side of the aperture. The measurements of the insertion loss are performed to verify the theoretical analysis.

• Journal of the Korean Society for Railway
• /
• v.19 no.5
• /
• pp.629-637
• /
• 2016

In this paper, an investigation was conducted to evaluate the acoustic performance of low height noise barriers installed adjacent to rails; an easy-to-use approximation formula was suggested for the evaluation of insertion loss (IL), instead of using the boundary element method. At first, the acoustic performance of the low height noise barriers was measured in an anechoic chamber using a scaled down model; the overall IL according to the source location was analyzed with the equivalent IL contour line. Using the measurement results obtained from the scaled down model, an approximation formula was suggested for the IL of low height noise barriers having various shapes. Also, the prediction program was validated through a comparison between the actual measurement results in the anechoic chamber and the prediction results. Finally, using the prediction program, an approximation formula for IL was suggested for the low height noise absorption barriers. Considering the frequency characteristics of the noise sources of the train, the absorptive low height noise barriers have a 'ㄱ' type shape, a height of 1.0m, and a length of 0.5m when they are installed on the structure gauge for the train.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.19 no.2
• /
• pp.237-243
• /
• 2008

This paper presents the backplane effects for two-wire transmission line with different line length crossing the rectangular aperture in an infinite ground backplane. The FDTD method is used to determine the characteristics of the backplane insertion loss and return loss of the transmission line in accordance with the transmission line spacing and additional wire lengths. The results show that the insertion gain is obtained for the narrow spacing of the transmission line and the insertion loss is appeared for the transmission line with the additional wire The measurements of return loss are performed to verify the theoretical analysis.

• Proceedings of the Optical Society of Korea Conference
• /
• 2002.07a
• /
• pp.260-261
• /
• 2002

파장 다중화(WDM) 방식의 광통신시스템에서 그림 1(a),(b)에 나타낸 바와 같이 한 쌍의 입출력 포트의 신호 방향을 바꾸는 광 가감기(Optical Add Drop Multiplexer)용의 2$\times$2 광 스위치가 사용된다 특히 멤스형 광 스위치는 삽입손실, 누화, 편광 및 파장 의존 손실 등이 낮아 많은 연구가 이루어지고 있다.(1-3) 광 스위치의 삽입손실을 낮추기 위해, 렌즈나 굴절률 맞춤액을 사용하는데, 광섬유를 정렬, 혹은 패키징할 때 렌즈나 맞춤액의 취급이 어렵다는 문제점이 있다. (중략)

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.191-196
• /
• 2000

본 논문에서는 공조용 소음기에 대한 삽입손실 및 압력손실과 같은 음향성능 평가를 위해 필요한 제반 사항을 ISO 7235에 근거하여 소개하였다. 이를 위해 시험설비의 종류 및 구비조건, 측정방법, 측정시 유의사항 등을 기술하였고, 이로서 공조용 소음기의 보다 정확한 음향성능평가가 이루어지도록 검토 하였다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2005.11b
• /
• pp.880-882
• /
• 2005

본 논문은 디지털 영상 데이터를 대상으로 웨이블릿 변환을 이용하여 주파수 영역에서 워터마크를 삽입하는 블라인드 워터마킹 알고리즘을 제안한다. 각기 다른 다양한 디지털 영상 데이터의 특성을 고려하여 영상의 특성을 반영하는 임계값을 적용하고 가우시안 랜덤 수열(Gaussian Random Sequence)을 워터마크로 삽입하여 원본영상과 워터마킹된 영상이 시각적으로 차이가 없도록 한다. 영상의 특성을 반영하기위한 임계값을 실험을 통하여 조절함으로서 영상의 손실정도, 워터마크 정보의 삽입 양, 검출 상관도 등의 관계를 연구하고 인간의 시각적인 특성을 고려하여 비가시도를 향상하였으며 중주파 대역에 워터마크를 삽입함으로서 원본영상의 손실을 최소화하고 다양한 영상 처리에 견고하도륵 하였다. 제안한 방법의 성능 평가를 위해서 JPEG 손실압축 선형 필터링, 비선형 필터링, 잡음첨가 그리고 크로핑 등의 영상 처리를 실험한 결과 높은 상관도와 견고함을 나타내었고 비가시도 측면에서도 시각적으로 인지할 수 없을 만큼 측정되었다.

• Journal of Software Assessment and Valuation
• /
• v.15 no.1
• /
• pp.109-114
• /
• 2019

In this paper, simulations of S-parameter and characteristic impedance for the probe pin are performed and its high-frequency performance is analyzed. The probe pins are arranged with one signal pin in the center and four ground pins on the top, bottom, left and right sides. The insertion loss and return loss of the probe pin are calculated while increasing the separation between the probe pins to 0.35 mm, 0.40 mm, and 0.50 mm, respectively. It is confirmed that the probe pin has different features of the insertion loss due to its periodic resonance phenomenon. Effect of the characteristic impedance on pitch and assignment of the probe pin is also analyzed. It is verified that there are a number of ground pins whose characteristic impedance is close to 50 Ω.

• Journal of the Microelectronics and Packaging Society
• /
• v.28 no.4
• /
• pp.97-101
• /
• 2021

In this study, Insertion loss according to the structural variant of interposer to Through Silicon Via (TSV) and Redistributed Layer (RDL) was studied through design of experiment. 3-Factors was considered as a variant, TSV depth, TSV diameter, RDL width with factor arrangement method and the response surface method from 400 MHz to 20 GHz. As a result, it was confirmed that as the frequency increased, the effect of RDL width was decreased and the effect of TSV depth and TSV diameter was increased. Also within the analysis range, to increasing RDL width, decreasing TSV depth, and fixing TSV diameter about 10.7 ㎛ was observed optimal result of Insertion loss.