• KIEE International Transactions on Electrophysics and Applications
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• v.5C no.4
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• pp.176-179
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• 2005

The increasing demand for high density packaging technologies and the evolution to mixed digital and analogue devices has been the con-set of increasing research in thin film multi-layer technologies such as the passive components integration technology. In this paper, Cu and TaO thin film with RF sputtering was deposited for spiral inductor and MOM capacitor on the $SiO_2$/Si(100) substrate. MOM capacitor and spiral inductor were fabricated for L-C band pass filter by sputtering and lift-off. We are analyzed and designed thin films L-C passive components for band pass filter at 900 MHz and 1.8 GHz, important devices for mobile communication system. Based on the high-Q values of passive components, MOM capacitor and spiral inductors for L-C band pass filter, a low insertion loss of L-C passive components can be realized with a minimized chip area. The insertion loss was 3 dB for a 1.8 GHz filter, and 5 dB for a 900 MHz filter. This paper also discusses a analysis and practical design to thin-film L-C band pass filter.

• Journal of the Korean Vacuum Society
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• v.16 no.6
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• pp.439-445
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• 2007

SiGe integrated circuits are being used in the field of high-speed wire/wireless communications and microwave systems due to the RF/high-speed analog characteristics and the easiness in the fabrication. Reducing the resistance variation in SiGe thin film resistors results in enhancing the reliability of integrated circuits. In this paper, we investigate the causes that generate the resistance nonuniformity after the silicon-based thin film resistor was fabricated, and consider the counter plan against that. Because the Ti-B precipitate, which formed during the silicide process of the SiGe thin film resistor, gives rise to the nonuniformity of SiGe resistors, the boron ions should be implanted as many as possible. In addition, the resistance deviation increases as the size of the contact hole that interconnects the SiGe resistor and the metal line decreases. Therefore, the size of the contact hole must be enlarged in order to reduce the resistance deviation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.665-667
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• 2010

In this paper, the method to detect the IM(Inter Modulation) components of power amplifier is proposed by using frequency down-convertor. Output signals of power amplifier which is coupled by 20dB coupler and divided by power divider are applied to RF and LO of the frequency converter. It could be found the magnitude of IM components of power amplifier as a converted DC voltage which is come from the difference between 3th and 5th IM component. The detected DC voltage values are changed from 0.72V to 0.9V when 3rd IM component level changed from -26.4dBm to +2.15dBm and 5th IM component level changed from -34.2dBm to -12.89dBm as the Vgs of 3W power amplifier is changed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.913-917
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• 2003

In the electronic components and devices fabrication, thin film resistors with low TCR(temperature coefficient of resistance) and high precision have been used over 3 GHz microwave in recent years. Ni-Cr alloys thin films resistors is one of the most commonly used resistive materials because it has low TCR and highly stable resistance. In this work, we fabricated thin film resistors using Evanohm alloys target(72Ni-20Cr-3Al-4Mn-Si) of s-type with excellent resistors properties by RF-sputtering. Also we reported best deposited conditions of thin film resistors for microwave to observe microstructure and electronic properties of thin film according to deposited conditions(between target and substrate, power supply)

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.3
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• pp.149-167
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• 2004

Passive components are indispensable in the design and development of microchips for high-frequency applications. Inductors in particular are used frequently in radio frequency (RF) IC's such as low-noise amplifiers and oscillators. This paper gives a broad overview on the on-chip spiral inductors. The design concept and modeling approach of the typical square-shaped spiral inductor are first addressed. This is followed by the discussions of advanced structures for the enhancement of inductor performance. Research works reported in the literature are summarized to aid the understanding of the recent development of such devices.

• Proceedings of the KIEE Conference
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• 2003.11b
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• pp.63-66
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• 2003

Resident mobile communication system technology has been developed. But, surged high voltages in antenna generally have damaged mobile communication. To solve this problem, we use arrester in Rx-Tx line system. That is, the arrester is to protect devices in system against considerable over-voltages or lighting strike. Currently, system protection using of arrester has been arrived in content level but these days, the fact of PIMD(Passive Intermodulation Distortion) which is RF passive components' nonlinear characteristic has appeared. This paper describes PIMD' causes occurred in arrester-estimated from Gas tube capsule, plating, temperature, humidity by experiment.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.11
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• pp.776-779
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• 2004

Resident mobile communication system technology has been developed. But, surged high voltages in antenna generally have damaged mobile communication. To solve this problem, we use an arrester in Rx-Tx line system. That is, the arrester is introduced to protect devices in system against considerable over-voltages or lighting strike. Currently, system protection using an arrester has arrived in a content level but these days, the PIMD(Passive Intermodulation Distortion) with RF passive components' nonlinear characteristic has appeared. This paper describes PIMD' causes occurred in arrester-estimated from Gas tube capsule. plating, temperature, and humidity by experiment.

• ETRI Journal
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• v.31 no.3
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• pp.324-326
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• 2009

We present the design of a compact microstrip lowpass filter with a wide stopband which is up to ten times the cutoff frequency. The filter is based on a coupled-line configuration and shunt open stubs. The open stubs create additional transmission zeros, which are used to extend the stopband of the filter without any additional components or cascaded units. A prototype lowpass filter with a 3 dB cutoff frequency of 0.428 GHz and a 15 dB stopband extended up to 4.77 GHz is fabricated to validate the theoretical predictions.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.6
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• pp.586-591
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• 2010

VLC (Visible Light Communication) is a wireless communication method using light that is visible to the human eye. It has a major advantage that it causes no interference to RF-based devices. This makes wireless communication possible in RF hazardous areas such as nuclear facilities. In order to apply VLC communication in harsh environment of nuclear power plant, the high luminance LEDs, which are key components of the VLC communication, have been gamma-ray irradiated at the dose rate of 4kGy/h during 72 hours up to a total dose of 288 kGy. The radiation induced color-center was formed in the LED housing cap made of transparent plastic or acryl material. The beam degradations of high luminance LEDs by high dose-rate gammaray irradiation are analyzed using color CCD image processing technology.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.16-20
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• 2002

This paper describes the resistive FET mixer with low IF for the 4-Ch DBF(Digital Beam Forming) receiver with LNA(Low Noise Amplifier). This DBF receiver based on the direct conversion method is generally suitable for high-speed wireless mobile communications. A radio frequency(RF), a local oscillator(LO) and an intermediate frequency(IF) considered in this research are 2.09 ㎓, 2.08 ㎓ and 10㎒, respectively. The RF input power, LO input power and Vgs are used -10㏈m, 6㏈m and -0.4 V, respectively. In the 4-Ch resistive FET mixer with LNA, the measured IF and harmonic components of 10㎒, 20㎒, 2.09㎓ and 4.17㎓ are about -12.5 ㏈m, -57㏈m, -40㏈m and -54㏈m, respectively. The IF output power observed at each channel of 10㎒ is about -12.5㏈m and it is higher 27.5 ㏈m than the maximum harmonic component of 2.09㎓. Each IF output spectrum of the 4-Ch is observed almost same value and it shows a good agreement with the prediction.