• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.551-552
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• 2008

This paper presets a results of frequency response in variation of wire bonding length. A gold ball bonding is used as a wire bonding process, and a DPDT(double pole double thru) switch is adapted as a device for test. Wire length is ranged from 442um to 833um and a measured frequency range is from 1 GHz to 6 GHz. Little difference are measured in insertion loss and return loss depending on wire length. Measured S21 and S11 are -0.58 dB and -17.7 dB, respectively. S21 insertion loss is rising up and S11 insertion loss is falling down as the frequency is increased.

• Journal of the Microelectronics and Packaging Society
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• v.28 no.2
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• pp.39-44
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• 2021

In this paper, two types of BPF(Band Pass Filter) which are hair-pin and interdigital have been designed for millimeter-wave application using two types of material which are LCP(Liquid Crystal Polymer) and PTFE(Polytetrafluoroethylene) and also, their performances such as bandwidth, insertion loss, and in-band flatness are compared. The proposed BPF are designed as third-order filters, and their pass band is from 26.5 GHz to 27.3 GHz. Interdigital BPF using PTFE substrate has most wide -3 dB S21 bandwidth of 7.8 GHz and hair-pin BPF using LCP substrate has most narrow -3 dB S21 bandwidth among the proposed four BPF. For in-band insertion loss, hair-pin BPF using PTFE substrate achieves low insertion loss better than -0.667 dB, and hair-pin BPF using LCP substrate exhibits relatively high insertion loss among the proposed four BPF better than -0.937 dB. However, the maximum difference in insertion loss performance among the proposed four BPF is 0.27 dB, which is too small to negligible. For in-band flatness, interdigital BPF using PTFE substrate shows greatest performance of 0.017 dB, and hair-pin BPF using LCP substrate exhibits the lowest performance of 0.07 dB. There are tiny difference in in-band flatness performance of 0.053 dB. As a results, it is considered that the BPF using LCP substrate can derive the performances similar to that of the BPF using PTFE substrate in Millimeter-wave band.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.11a
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• pp.124-128
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• 2001

We apply for the first time a low cost and loss wafer level packaging technology for RF-MEMS device. The proposed structure was simulated by finite element method (FEM) tool (HFSS of Ansoft). S-parameter measured of the package shows the return loss (S11) of 20dB and the insertion loss (S21) of 0.05dB.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.21 no.4
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• pp.357-364
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• 2011

In this study, ring-shaped acoustic resonators were proposed to be installed in a silencer to increase the acoustic performance of silencer in the low-frequency range. Evaluation of noise reduction performance of acoustic resonator arrays was carried out by measuring the random-incidence absorption coefficient. It was found that the absorption coefficient of resonator array was measured up to 1 at 125 Hz of 1/3-octave band center frequency. Insertion losses of silencers with ring-shaped acoustic resonator arrays were measured based on ISO 7235. The results were shown that the ring-shaped resonator could increase the insertion loss up to 13 dB without flow, whereas 7 dB when flow speed reached 15 m/s. As increasing the flow speed above 15 m/s, the effect of acoustic resonator decreased due to the effect of nonlinear air damping of the resonator. It was also found that the increment of pressure drop by the presence of resonator arrays was about 9 % at flow speed of 25 m/s.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.2
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• pp.107-114
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• 2009

In this paper, high efficiency amplifier configuration is proposed using the reconfigurable power divider. In order to enhance average efficiency of linear power amplifiers for wireless communication, it is required to increase efficiency in low output power region. The proposed power divider operates in two modes, high power mode and low power mode, according to output power. In each mode, it allows impedance matches and low loss, which is made possible by employing two $\lambda/4$ coupled lines and two switches. The fabricated power divider shows the return loss ($S_{11}$) and insertion loss ($S_{21}$) of -16.49 dB and -0.83 dB, respectively, in low power mode. In high power mode, the measured return loss ($S_{11}$) and insertion loss ($S_{31}$) are -16.28 dB and -0.73 dB, respectively. This result successfully demonstrates the reconfigurability of the proposed power divider.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2006.10a
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• pp.255-267
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• 2006

LTCC Technology is very suitable for 60 GHz application $\blacksquare$ LTCC substrate shows low loss at 60 GHz. - low insertion and return losses $\blacksquare$ Microstrip or CBCPW line is sultable for transmission lines at 60 GHz. - low loss (0.1dB/mm) $\blacksquare$ Single ribbbon bonding is adequate for interconnection - simple - low loss (0.1dB/bonding) $\blacksquare$ Characteristics of MMIC module - Gain difference (${\Delta}S21$) : 0.4 dB

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

• Journal of information and communication convergence engineering
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• v.4 no.3
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• pp.108-110
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• 2006

Film bulk acoustic resonators for radio frequency wireless applications are presented. Various simulations and modeling were carried out. The impedance of a five-layered FBAR showed almost the same trend of the wideband characteristics as that of an ideal FBAR, but the characteristics of the higher modes appear to be much more suppressed. In addition, the wideband impedance decreased with increasing device size. The resonance characteristics depend strongly on the physical dimensions.

• Journal of the Korean Institute of Telematics and Electronics
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• v.18 no.3
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• pp.21-24
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• 1981

A simple optial fiber Y-branch is fabricated using micro - torch and fusion splicer. Tapered end of two fibers - in -contact is spliced with another fiber. Total insertion loss is 26dB and optical power branchi ng ratio is 0.98. Using fiber Y-branch, an UTDR with simple optical system is realized The resolution of the OTDR is $\pm$ 5m in length and t 0.5 dB/km in loss coefficient.

• Journal of the Korean Ceramic Society
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• v.40 no.6
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• pp.547-552
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• 2003

ZnO thin films on glass substrate were deposited by RF magnetron reactive sputtering at 100 W, 1.33 Pa, Ar/O2=50 : 50, 200$^{\circ}C$, and a target/substrate distance of 4 cm. Crystallinities, surface morphologies, chemical compositions, and electrical properties of the films were investigated by XRD, SEM, AFM, RBS, and electrometer. All films showed a strong preferred c-axis orientation and the chemical stoichiometry. The propagation velocity of ZnO/IDT/glass of single electrode and double electrode types SAW filter was about 2,589 m/sec, 2,533 m/sec and insertion loss was a minimum value of about -11 dB and -21 dB, respectively.