• IEIE Transactions on Smart Processing and Computing
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• v.5 no.3
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• pp.164-168
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• 2016

A low insertion-loss, high-isolation switch based on single pole double throw (SPDT) for a 2.4GHz Bluetooth low-energy transceiver is presented in this paper. In order to increase isolation, the body floating technique is implemented. Based on characteristics whereby the ratio of the sizes of the shunt and the series transistors significantly affect the performance of the switches, the device sizes are optimized. A simple matching network is also designed to enhance the insertion loss. Thus, the SPDT switch has high isolation and low insertion loss without increasing the complexity of the circuit. The proposed SPDT is designed and simulated in a complementary metal-oxide semiconductor 65nm process. The switch has a $530{\mu}m{\times}270{\mu}m$ area and achieves 0.9dB, 1.78dB insertion loss and 40dB, 41dB isolation of transmission, reception modes, respectively.

• Journal of Korean Dental Science
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• v.2 no.1
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• pp.42-47
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• 2009

Objective : The purpose of this study was to evaluate the effects of low level lasers on bone healing and new bone formation around titanium dental implants in canine models. 18 oxidized surface treated implants and a Dens-bio laser were used. Study design : Low level lasers were irradiated with a total of 8J for 4 minutes by pulse wave type and 1 minute by continuous type. For the experimental group, a low level laser was used to irradiate the first premolar implant's insertion area at the time of insertion, a low level laser was used to irradiate the second premolar implant's insertion area daily for one week after implant insertion, and a low level laser was used to irradiate the third molar implant's insertion area daily for 2 weeks postoperatively. At the conclusion of the study, sacrificed tissue sections were made from investing tissue and observed under an optical microscope. Results : The rate of new bone formation around the implant showed no significant difference between the control group and the experimental group. New bone formation rates of the control and experimental group 2 weeks following implant placement were higher than that of immediately after implant placement and 1 week after implant placement. Conclusions : Based on these results, a low-level laser showed no statistically significant increase in bone formation following implant placement.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.350-354
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• 2008

Low frequency exhaust noise of marine diesel engine is one of the most important noise sources in vessels. However, conventional absorptive silencers are limited because the absorptive material is not effective in low frequency range. In the paper, exhaust noise control of marine diesel engine has been studied by using the resonator type silencer, which was composed of concentric hole-cavity resonators. The acoustic performance of the resonator type silencer was verified by the insertion loss measurement considering flow effect. Consequently, its high performance, about $5{\sim}8dB$ noise reduction, in the low frequency range was confirmed by insertion loss measurements conducted in the ship.

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

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.489-492
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• 2000

This paper describes a new transient voltage suppressor(TVS) with a low insertion loss and a very wide frequency bandwidth to protect antenna circuit from transient voltages. Conventional protection devices have some problems such as low frequency bandwidth and high insertion loss. In order to improve these limitations, a coaxal type TVS, which consists of a gas tube is developed. The performance of the proposed transient voltage suppressor is tested by using a combination surge generator specified in IEC 61000-4-5 standard and by using a network analyzer of 40 MHz ∼ 5GHz bandwidth. From the experimental results, it is confirmed that the proposed TVS has an enough protection performance in low insertion loss and in wide frequency bandwidth

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.1166-1169
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• 2005

This paper describes a new transient voltage suppressor(TVS) with a low insertion loss and a high cut-off frequency to protect antenna circuit from transient voltages. Conventional protection devices have some problems such as a low frequency bandwidth and a high insertion loss. In order to improve these limitations, a coaxal type TVS, which consists of a gas tube is developed. The performance of the proposed transient voltage suppressor is tested by using a combination surge generator specified in IEC 61000-4-5 standard and by using a network analyzer of 40 MHz ${\sim}$ 5 GHz bandwidth. From the experimental results, it is confirmed that the proposed TVS has an enough protection performance in a low insertion loss and a high cut-off frequency.

• ETRI Journal
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• v.35 no.4
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• pp.638-643
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• 2013

This paper presents a 5-bit digital step attenuator (DSA) using a commercial 0.18-${\mu}m$ silicon-on-insulator (SOI) process for the wideband phased array antenna. Both low insertion loss and low root mean square (RMS) phase error and amplitude error are achieved employing two attenuation topologies of the switched path attenuator and the switched T-type attenuator. The attenuation coverage of 31 dB with a least significant bit of 1 dB is achieved at DC to 20 GHz. The RMS phase error and amplitude error are less than $2.5^{\circ}$ and less than 0.5 dB, respectively. The measured insertion loss of the reference state is less than 5.5 dB at 10 GHz. The input return loss and output return loss are each less than 12 dB at DC to 20 GHz. The current consumption is nearly zero with a voltage supply of 1.8 V. The chip size is $0.93mm{\times}0.68mm$, including pads. To the best of the authors' knowledge, this is the first demonstration of a low phase error DC-to-20-GHz SOI DSA.

• Journal of KSNVE
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• v.4 no.3
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• pp.377-384
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• 1994

This paper is an investigation of the performance of absorption diffusers to suppress the vent noise emitted when high pressure gas is throttled. First, experiment for the static performance is carried out. When there is no through-flow, the insertion loss has been obtained in terms of 1/3 octave band spectrum and the effect of the number of diffusers and the thickness of the absorption material on the static performance has been obtained. And the similarity in the spectrum of the static insertion loss is confirmed by comparing two similar models with different size. Second, the dynamic performance has been obtained by experiment using blow-down of compressed air from a storage tank through an orifice of diameter 10 mm. The back pressure by the diffuser is measured and compared with that of a single diffuser. It is found that the insertion loss of asingle diffuser is very low around 3 dB at high frequencies with negative value at low frequencies. By absorption material between the diffuser tubes, however, the performance is increased considerably. Without flow the static insertion loss increases by 3 - 4 dB by doubling the thickness or the density of the absorptionmaterial. With flow, however, the dynamic insertion loss increases. While, the back pressure by the diffuser is small enough to be neglected.

• Journal of Chest Surgery
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• v.57 no.3
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• pp.281-288
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• 2024

Background: Venoarterial extracorporeal membrane oxygenation (ECMO) is a key treatment method used with patients in cardiac arrest who do not respond to medical treatment. A critical step in initiating therapy is the insertion of ECMO cannulas. Peripheral ECMO cannulation methods have been preferred for extracorporeal cardiopulmonary resuscitation (ECPR). Methods: Patients who underwent ECPR at Daegu Catholic University Medical Center between January 2017 and May 2023 were included in this study. We analyzed the impact of 2 different peripheral cannulation strategies (surgical cutdown vs. percutaneous cannulation) on various factors, including survival rate. Results: Among the 99 patients included in this study, 66 underwent surgical cutdown, and 33 underwent percutaneous insertion. The survival to discharge rates were 36.4% for the surgical cutdown group and 30.3% for the percutaneous group (p=0.708). The ECMO insertion times were 21.3 minutes for the surgical cutdown group and 10.3 minutes for the percutaneous group (p<0.001). The factors associated with overall mortality included a shorter low-flow time (hazard ratio [HR], 1.045; 95% confidence interval [CI], 1.019-1.071; p=0.001) and whether return of spontaneous circulation was achieved (HR, 0.317; 95% CI, 0.127-0.787; p=0.013). Low-flow time was defined as the time from the start of cardiopulmonary resuscitation to the completion of ECMO cannula insertion. Conclusion: No statistically significant difference in in-hospital mortality was observed between the surgical and percutaneous groups. However, regardless of the chosen cannulation strategy, reducing ECMO cannulation time was beneficial, as a shorter low-flow time was associated with significant benefits in terms of survival.

• International Journal of Advanced Culture Technology
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• v.10 no.4
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• pp.555-560
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• 2022

In this study, the insertion loss and phase delay according to the multi-layer structure radome parameters were analyzed using the boundary value solution approach, and the multi-layer structure and hexa mesh structures with low-loss electrical characteristics for the Ku-band transmission/reception frequency of 10.7 ~ 14.5 GHz were designed and manufactured. A hexa mesh was applied to minimize radio wave transmission and scattering, which lowered the transmittance refractive index according to the radio incident angle and minimized dielectric loss through high-density foam. Similar to the simulation result, the transmission loss obtained the gain in a specific receiving frequency band, and in the transmission frequency band, an excellent low loss characteristic was obtained with an insertion loss of 0.8dB or less. The results of this study can be used in radio transmission radomes of low-weight, low-cost end-system protection devices.