• Journal of the Korean Society for Aviation and Aeronautics
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• v.25 no.3
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• pp.68-73
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• 2017

In this study, we design a low-cost test equipment for real-time image observation and transmission/reception distance test using 1m by 1.5m bang-pai kite. The image observation is made by using two servo motors to enable the camera to control the two axis attitude. The image observation equipment is hung on the string of a kite and the test is performed to observe the real time image. The transmission and reception distance test of the wireless RF transceiver module is conducted on the ground and in the air.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.8
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• pp.863-870
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• 2003

The digital transmission system entered in a RF region as digital system use IC chips of the speeder edge rate and clock speed nowadays. Optical path really was used in order to obtain the more capacity. In this paper, we described importance of electrical interconnect to get the signal integrity in optical module by simulation and experiment. 12 channel${\times}$2.5 G/ps optical parallel transmitter modules were manufactured by two different method ; access lines with microstrip and stripline type. We have clearly shown that the optical module adopting microstrip type with S$\sub$11/ $\geq$ -10 dB presents distortion but the optical module adopting stripline type with S$\sub$11/ $\leq$ : 15 dB obtains eye opening in 2.5 Gbis optical eye pattern response.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.10
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• pp.687-698
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• 2001

This paper presents a three dimensional stacked pad area away (PAA) package configuration as an implementation method of radio frequency (RF) circuits. 224MHz RF circuits of intelligence traffic system(ITS) were constructed with the stacked PAA RF pakage configuration. In the process of manufacturing the stacked PAA RF pakage, RF circuits were partitioned to subareas following their function and operating frequency. Each area of circuits separated to each subunits. The operating characteristics of RF PAA package module and the electrical properties of each subunits were examined. The measurement of electrical parameters for solder balls which were interconnects for stacked PAA RF packages showed that the parasitic capacitance and inductance were 30fF and 120pH, respectively, which might be negligible in PAA RF packaging system. HP 4396B network/spectrum analyzer revealed that the amplification gain of a receiver and transmitter at 224 MHz was 22dB and 27dB, respectively. The gain was 3dB lower than designed values. The difference was probably generated from fabrication process of the circuits by employing commercial standard

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.57-63
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• 2016

This paper describes implementation of the RF frequency synthesizer with $0.18{\mu}m$ silicon CMOS technology being used as an application of the IEEE802.15.4g SUN sensor node transceiver modules. Design of the each module like VCO, prescaler, 1/N divider, ${\Delta}-{\Sigma}$ modulator, and common circuits of the PLL has been optimized to obtain high speed and low noise performance. Especially, the VCO has been designed with NP core structure and 13 steps cap-bank to get high speed, low noise, and wide band tuning range. The output frequencies of the implemented synthesizer is 1483MHz~2017MHz, the phase noise of the synthesizer is -98.63dBc/Hz at 100KHz offset and -122.05dBc/Hz at 1MHz offset.

• Journal of KIISE:Information Networking
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• v.37 no.3
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• pp.217-227
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• 2010

To apply active RFID technology in the various kinds of industry, it needs to quickly transmit a large amount of data. ISO/IEC 18000-7 standard uses the 433.92MHz as single channel system and its transmit rate is just 27.8kbps, that is insufficient for a large amount of data transmission. To solve this problem, we designed a new data transmission protocol using 2.4GHz band. The feature of designed protocol is not only making over 255bytes data messages using the Burst Read UDB but also efficiently transmitting it. To implement this protocol, we use Texas Instruments's SmartRF04 develop kit and CC2500 transceiver as RF module. As an evaluation of 63.75kbytes data transmission, we demonstrate that transmission time of Burst Read UDB has improved as 17.95% faster than that of Read UDB in the ISO/IEC 18000-7.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.5
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• pp.1120-1128
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• 2004

In this paper, we has designed and implemented Up-converter for K-band with high IMD3 performance using balanced power amplifier. It is consisted of PA module and, Local Oscillator module with reject Filter, mixer module and If block, and Up-converter has a local loop path to decide whether it operate or not and has the sensing port to inspect output power level. According to the power budget of designed Up-converter, K-band balanced power amplifier was fabricated by commercial MMIC. Measurement results of up-converter show about 40dB Gain, PldB of 29dBm and OIP3 was 38.25dBm, that is good performance compared to power budgets. We has adjusted gate voltage of MMIC to control more than 30 dB gain. This up-converter was used in transceiver for PTP and PTMP, and applied to digital communication system that use QAM and QPSK modulation.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.2
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• pp.93-100
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• 2009

This paper presents a step up four channel DC-DC converter using charge pump voltage doubler structure. Our goal is to design and implement DC-DC converter for capacitive SP4T RF MEMS switch in front end module in wireless transceiver system. Charge pump structure is small and consume low power 3.3V input voltage is boosted by DC-DC Converter to $11.3{\pm}0.1V$, $12.4{\pm}0.1V$, $14.1{\pm}0.2V$ output voltage With 10MHz switching frequency. By using voltage level shifter structure, output of DC-DC converter is selected by 3.3V four channel selection signals and transferred to capacitive MEMS devices. External passive devices are not used for driving DC-DC converter. The total chip area is $2.8{\times}2.1mm^2$ including pads and the power consumption is 7.52mW, 7.82mW, 8.61mW.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.5 s.347
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• pp.77-83
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• 2006

In this paper, we designed, constructed and evaluated the system for the FTTH suited to a residence and apartment using CWDM-PON techniques. These systems have capacity to service at 100Mbps rate to 384 users in the same breath. Also, the services include the internet, CATV, IPTV and wireless LAN. In the case of ire network, the data could be transmitted by UTP cable and optical fiber and case of wireless one, the data transmitted using WLAN. The distance between the cental office and the user is 20km and the data rate is 100Mbps maximum. Of course, the optical network used just one fiber optical core. For the basic material, we obtained the characteristics of optical transceiver module, Mux/Demux and transmission qualities depends on the environment.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.4
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• pp.425-430
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• 2013

Robust and high speed underwater communication is severely limited when compared to communications in terrestial. In free space, RF communication operates over long distances at high data rates. However, the obstacle in seawater is the severe attenuation due to the conducting nature. Acoustic modems are capable of long range communication up to several tens of kilometers, but it has low data-rate, high power consumption and low propagation speed. An alternative means of underwater communication is based on optics, wherein high data rates are possible. In this paper, the characteristics of underwater channel in the range of visible wavelength is investigated. And the possibility of optical wireless communication in underwater is also described. The LED-based transceiver and CMOS sensor module are integrated in the system, and the performance of image transmission was demonstrated.