• Journal of Positioning, Navigation, and Timing
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• v.13 no.3
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• pp.341-353
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• 2024

This paper presents the design results of a Multi-band Global Positioning System (GPS)/Korean Positioning System (KPS) Real-Time Kinematics (RTK) precise positioning simulator and evaluate its functionalities. The designed simulator consists of a trajectory generation module, a Radio Frequency (RF) signal generation module, a RF signal reception module, a coarse positioning module, a precise positioning module, and an error statistics reporting module. Simulations in realistic scenarios confirm that the proposed baseband simulator works appropriately. The developed simulator can adjust the type, number, band, and Pseudo Random Noise (PRN) code type of the satellite constellation in various ways, and the practical positioning performance can be tested. It can also reflect the channel influence at the actual RF stage and the influence during the initial synchronization and tracking process. Considering such advantages, the proposed simulator would be useful in future researches and developments related to KPS.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.39 no.3
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• pp.98-109
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• 2002

Bluetooth technology is a publicly available specification proposed for Radio Frequency (RF) communication for short-range :1nd point-to-multipoint voice and data transfer. It operates in the 2.4㎓ ISM(Industrial, Scientific and Medical) band and offers the potential for low-cost, broadband wireless access for various mobile and portable devices at range of about 10 meters. In this paper, we describe the structure and the test results of the bluetooth baseband module with direct memory access method we have developed. This module consists of three blocks; link controller, UART interface, and audio CODEC. This module has a bus interface for data communication between this module and main processor and a RF interface for the transmission of bit-stream between this module and RF module. The bus interface includes DMA interface. Compared with the link controller with FIFOs, The module with DMA has a wide difference in size of module and speed of data processing. The small size module supplies lorr cost and various applications. In addition, this supports a firmware upgrade capability through UART. An FPGA and an ASIC implementation of this module, designed as soft If, are tested for file and bit-stream transfers between PCs.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.666-668
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• 2004

본 논문에서는 RF를 이용한 다용도 디지털 데이터 통신 모듈의 설계와 제작에 관하여 논하였다. RF통신에 대한 기본적인 이론과 적용범위 등을 살펴보았고, 신뢰성 있는 통신을 위해 나름의 프로토콜을 적용하였다. 통신거리 개선을 위해 전력증폭기 시뮬레이션, 안테나 임피던스 매칭에 관한 연구를 해 보았다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.4
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• pp.362-370
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• 2010

In this paper, a compact RF Front-end module for Wireless Fidelity(Wi-Fi) and Worldwide Interoperability for Microwave Access(WiMAX) applications is realized by low temperature co-fired ceramic(LTCC) technology. The RF Front-end module is composed of three LTCC band-pass filters, a Film Bulk Acoustic Resonator(FBAR) filter, fully embedded matching circuits, an SPDT switch for mode selection, an SPDT switch for Tx/Rx selection, and an SP4T switch for band selection. The parasitic elements of 0.2~0.3 pF are generated by the structure of stacking in the top pad pattern for DC block capacitor of SPDT switch for mode selection. These kinds of parasitic elements break the matching characteristic, and thus, the overall electrical performance of the module is degraded. In order to compensate it, we insert a parallel lumped-element inductor on capacitor pad pattern for DC block, so that we obtain the optimized performance of the RF Front-end module. The fabricated RF front-end module has 12 layers including three inner grounds and it occupies less than $6.0mm{\times}6.0mm{\times}0.728mm$.

• Proceedings of the IEEK Conference
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• 2000.06e
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• pp.187-190
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• 2000

We presents the construction of radio frequency pad area array package modules which operate at radio frequency of 224MHz, and proposes the structure of RF module packages to improve its electrical characteristics. The module of RF PAA package was constructed in the configuration of three dimensional stacked package and reduced size. RF PAA packages showed the optimized and improved gain of 2dB by partitioning the RF transceiver with 3 dimensional stacked PAA packages.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.27 no.12
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• pp.815-819
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• 2014

Aluminum nitride (AlN) thin film and TiN film as a buffer layer were deposited on INCONEL 600 substrate by reactive RF magnetron sputtering at room temperature(R.T.) under 25~75% $N_2/Ar$ atmosphere. The as-deposited AlN films at 25~50% $N_2/Ar$ showed a polycrystalline phase of hexagonal AlN, and an amorphous phase. The peak of AlN (002) plane, which was determinant on a performance of piezoelectric transducer, became strong with increasing the $N_2/Ar$ ratio. Any change in the preferential orientation of the as-deposited AlN films was not observed within our $N_2$ concentration range. The piezoelectric sensing properties of AlN module were performed using pressure-voltage measurement system. The output signal voltage of AlN module showed a linear behavior between 20~80 mV in 1~10 MPa range, and the pressure-sensing sensitivity was calculated as 3.6 mV/MPa.

• The Journal of the Korea institute of electronic communication sciences
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• v.1 no.1
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• pp.8-19
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• 2006

The RF Module which can be adjusted for a digital terrestrial and multi standard(DVB-C, ISDB-T, DVB-H) reception is developed. The Module by single conversion does divide a broadband(45MHz~860MHz) broadcasting channels into three-bands(UHF, VHF_HIGH, VHF_LOW) to satisfy some electrical performances such as image signal rejection, phase noise, IF flatness etc and digital reception specifications such as analog and digital adjacent channel protection, co-channel protection which is important in environment with co-existence both analog and digital broadcasting systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3A
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• pp.345-355
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• 2006

The RF Module which can be adjusted for a digital terrestrial and multi standard(DVB-C, ISDB-T, DVB-H) reception is developed. The Module by single conversion does divide a broadband($45MHz{\sim}860MHz$) broadcasting channels into three-bands(UHF, VHF_HIGH, VHF_LOW) to satisfy some electrical performances such as image signal rejection, phase noise, IF flatness etc and digital reception specifications such as analog and digital adjacent channel protection, co-channel protection which is important in environment with co-existence both analog and digital broadcasting systems.

• Proceedings of the IEEK Conference
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• 2000.06e
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• pp.89-92
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• 2000

A wire communication module for PLC controller was developed. This system consists of RF module interface part, RS232 serial communication control part, LED display part and control S/W with GUI interface. RF communication frequency is controlled by PLL controlling and communication rate is also controlled as 1200 and 4800 bps. Communication and control status are displayed on LED. As a S/W part, graphic user interface on Window 95 O.S. was developed. To show the validity of the developed system, severial communication and control of PLC system were experemented.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.231-234
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• 2001

OBD-II regulations are already effective in many countries. The California Air Resources Board(CARB) first issued regulations in 1985 for the 1988 model year, known as OBD-I, and required the vehicle's engine management computer to warn the driver by means of a dash-mounted light if a malfunction occurred in either the oxygen sensor, the exhaust gas recirculation(EGR) valve or the evaporative emission system purge solenoid, and to store information on troubles that have no recurrent characteristics. This paper presents two methods of wireless monitoring OBD signal, which is one of the ECU output for self diagnostic measurement. RF module is used to monitor ECU's Self diagnostic signal remotely. Two kinds of measurement systems which are based on micro-controller(80C196KC) for portable detection and PC for sever are considered for receiving the RF signal. Therefore, possibility of real-time monitoring of ECU's self diagnostic signal remotely is verified on this paper.