• International Journal of Contents
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• v.6 no.2
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• pp.6-9
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• 2010

Using symplectic relation and reaction concept, we propose a planar near-field antenna measurement method. A generalized probe compensation equation is deduced to obtain the probe correction formulation. To verify our approach, a reflector antenna with $1{\times}2$ horn array is fabricated and measured in the near-field measurement facility. The near-field measurement results are compared with the physical optics (PO) simulation. The results of measurement and simulation agree very well near to the mainbeam.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.10
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• pp.1917-1922
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• 2010

Near-Field Communication (NFC) is a short-range wireless communication technology evolved from RFID especially for the exchange of data between active and passive devices. This paper presents the mathematical models for the signal path of a NFC transceiver system and a behavioral simulation platform using MATLAB simulink. The approximated mathematical models simplify the simulation complexity of a transceiver and provide a quick evaluation. With this calculation platform, we can evaluate the system performance caused by the noise and the non-linearity of the individual blocks, and caused by system variables such as Effective Number of Bits (ENOB) of ADC and filter cutoff frequency. This platform provides us with a rapid prototyping, a reliable system design, and an efficient risk management during development of the NFC transceiver ICs.

• Proceedings of the Korea Contents Association Conference
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• 2004.11a
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• pp.280-284
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• 2004

In this paper, we propose a low-cost near-field measurement system using a circular cylindrical scanning formula in order to obtain the radiation pattern of an AUT (Antenna Under Test). Near-field measurement is performed with the improved circular cylindrical scanning based on a planar scanning. We propose a novel method that replaces a network analyzer and we also offer the specifications of the near-field measurement system.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.11
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• pp.1217-1224
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• 2015

The doorlock using buttons has been widely used since it does not exploit the physical key and has much functions though it is cheap. However, the doorlock has problems where it is easy to forget the secret number since the user has to remember the number and difficult to keep secure when the one secret number has been used for a long time. In this paper, we propose the doorlock system using the near field communication. The proposed system controls the open and close of the doorlock using user data acquired by the near field communication tag, The implemented doorlock system has the benefit to control the doorlock without a secret number.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.4
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• pp.105-111
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• 2019

In this paper, a performance analysis of waveguide broad-wall slot array antenna for millimeter-wave seeker in Ka-band was performed as using near-field measurement. The measurement of slot array antenna was conducted in both far-field and near-field. And the validation of near-field test in millimeter band was confirmed. It was confirmed that the beam pattern characteristics including beam width and side lobe level of the slot array antenna that performed the verification were the same. Differenced in the side lobe level of azimuth and elevation beam pattern were verified to be less than 1dB. Additionally, the new antenna aperture distribution was extracted as using back-projection method modifying the near-field data and then introduced the method conducting performance analysis of array antenna.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.2 no.1
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• pp.65-72
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• 2009

For the evaluation of far-field performance by using the near-field probing on the base station dipole array antenna, the effects of mutual coupling depending on the heights between the array antenna with reflector and the probe were analyzed. When the height is varied in the near-field region, S parameters on the input ports of antenna and probe are measured and analyzed to decide the height for the minimum mutual coupling effect and the maximum probing efficiency. This height will be applicable to the near-field probing system design to achieve the precision far-field performance of a base station array antenna system.

• Journal of IKEEE
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• v.19 no.4
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• pp.617-624
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• 2015

In this paper, an adult authentication system based on authentication certificate was designed and implemented using smartphone and near-field communication. It has three advantages. First, it achieves easy, convenient, and fast authentication by using smartphone and near-field communication. Second, it achieves extremely high security and reliability by exploiting authentication certificate. Third, it achieves extremely low risk of personal information leakage by generating and sending only virtual identification code. Finally, it has a proper legal basis by Digital Signature Act. It consists of adult authentication module, near-field communication control module, policy server module, and database server module. A prototype of the proposed system was designed and implemented, and it was verified to have correct operation.

• Smart Media Journal
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• v.2 no.3
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• pp.10-16
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• 2013

NFC (Near Field Communication) was developed by SONY, NXP in 2002 and in 2003 respectively. It is one type of standard shore-range wireless communication system which operates in 13.56 MHz frequency band, within 10 cm distance and enables data transfer between devices with maximum rate of 424kbps. Various studies have been done on NFC technology and many handset manufacturers such as Apple, Google, Samsung Electronics Co., are trying to expand their market for new mobile services using this technology. This paper analyses the NFC standard technology, its trends and prospects in chapter II, which is followed by NFC systems and communication method in chapter III, and eventually NFC trends and future views is explained in chapter IV.

• Journal of Korea Multimedia Society
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• v.17 no.5
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• pp.613-622
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• 2014

In spite of the convenience and cost-effectiveness of an electronic document management system the paper-type documents still should be stored for a comparison against the original documents. In this paper, for the efficient management of paper documents, we designed and implemented a document management system using smart devices equipped with NFC(Near Field Communication) technology. To implement the proposed system we designed a database for document management and developed an Android application for smart device using Eclipse 3.0 and Java programming. Whenever we touch the smart phone on the NFC tags which are attached to the paper-type documents and document boxes, it is possible to registering, searching and carrying in and out services for documents and boxes. This study provides smart phone users with systematic, economical and convenient paper-type documents management functions, and thus enhances the business efficiency.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.10
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• pp.907-913
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• 2015

This work presents a method to predict the near magnetic field distribution on the digital switching circuit mounted on PCB using co-simulation of circuit and electromagnetic fields. The proposed method first obtains the normalized near field distribution by exciting the signal and power ports of the switching circuit using sinusoidal sources. Then the real near magnetic field distribution is determined by weighting the normalized field distribution using the current spectrum of the switching circuit. To confirm the proposed method, a switching IC with a ring oscillator and a output buffer is fabricated and measured in the form of chip-on-board. The surface magnetic field distribution is measured using a magnetic probe above the PCB and compared with the simulation results. Experimental results show the correspondence between simulation and measurement results within 10 dB up to fifth harmonics.