• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2004.07a
• /
• pp.313-313
• /
• 2004

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2004.07a
• /
• pp.308-308
• /
• 2004

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2004.11a
• /
• pp.427-427
• /
• 2004

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 2004.11a
• /
• pp.404-404
• /
• 2004

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.11 no.3
• /
• pp.1-8
• /
• 2011

In this paper, data transmission corrugated horn antenna for RF sensor satellite system and its radiation characteristic are presented. The proposed antenna is designed, fabricated and measured to obtain the maximum gain at ${\pm}60^{\circ}$ of its radiation patterns. The result of the proposed antenna is that the return loss is less than -15 dB and the gain is over 5 dBi at ${\pm}60^{\circ}$ of its radiation patterns. From these results, it is confirmed that the proposed can be used as data transmission corrugated horn antenna for RF sensor satellite system.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.6C
• /
• pp.611-618
• /
• 2009

Recently, an indoor location-aware technology has been focused on as a key technology for context awareness in ubiquitous computing environments. The conventional Cricket system was designed with a non-centralized architecture, which has advantages in terms of user privacy, deployment, scalability, decentralized administration, network heterogeneity, and low cost. In this paper, an indoor location system based on TDOA between RF and ultrasound signals is designed, which improves the Cricket system. A 2.4GHz frequency is employed for transmitting RF messages, which is in an ISM band. The beaconing frequency is doubled to enhance the channel utilization rate. The ultrasonic pulse duration is optimized to increase the coverage of ultrasonic signals. The function of calculating location coordinates is embedded in a listener. The location-update rate and location accuracy are also improved.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.10 no.10
• /
• pp.1905-1913
• /
• 2006

The researches about the hardware and the software implementing ubiquitous sensor network have great rush in recent years. This paper deals the development of a sensor node with the dual interface which also has an RF wireless interface while has an Bluetooth interface used widely in present. This sensor node includes a Atmeg32 microcontroller, a Bluetooth module, a RF module. a temperature-humidity sensor. and I also develop the F/Ws controlling each modules with C language using GCC compiler. The sensor node developed can reaches 15m with Bluetooth interface and 60m with RF interface. It works stably with the voltage above 5V and it consumes currents 21mA average in idle mode, 63mA average in active mode.

• 한국정보통신설비학회:학술대회논문집
• /
• 2002.08a
• /
• pp.17-20
• /
• 2002

본 논문에서는 세라믹 칩 안테나를 LTCC로 구현하여 다중 대역 특성을 얻는 방법을 제안하고 있다. 휴대용 단말기에 칩 안테나를 내장함으로 물리적 손상을 피하고 위치추적 시스템(GPS) 대역과 단말기 송수신용 대역, 즉 두 대역 이상 사용 가능하고 ${\varepsilon}_r=7.8$인 세라믹 칩 안테나를 LTCC(Low Temperature Co-fired Ceramic)공정을 이용하여 세라믹 칩 내부에 정합 회로를 구현하여 이중 대역 특성을 갖는 구조에 대해 논의하고 있다. 안테나의 전체 크기는 $16mm{\times}4mm{\times}2mm$ 이며 대역폭은 삽입손실 -10dB 기준 대략 1560MHz에서 2160MHz까지 약 600MHz정도이다. 측정은 접지면의 넓이가50mmx50mm이고 두께=0.7874mm, ${\varepsilon}_r=4.6$인 FR4 기판을 이용하여 측정한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2003.10a
• /
• pp.626-629
• /
• 2003

In this paper, a system that implementation of Biometric System Using RF-ID. We organize a certification system which the security is strengthened, the information is flowed out and the presentation will do the possibility not to be abused. The loss of the credit card and problems which there is many of forgery back are happening. To solve such problems, We organized the system to use after we stored a fingerprint data at RF Card and going through certification necessary formalities. Various research to be related uses this system and is predicted. The development to common use goods will be possible through a certification procedure.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.8
• /
• pp.1813-1819
• /
• 2011

In this research, the location positioning system supposed is concerned with range recognition technology using phase and magnitude of radio wave and adding technology of image histogram by vision. By the proposed technology, we design the radio transmitter and receiver and realize the measurement system, and save the data in disk that is earned from 900Mhz RF signal, middle frequency 450Khz of analog signal. Range information is earned the data through digital signal processing of IF signal. For the estimation of range measured, we analyze the difference between real range and measurement range, and also suggest the method to improve the measurement error using average processing and amplitude properties.