• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.4
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• pp.366-372
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• 2002

A wideband stacked patch antenna fed by an L-strip feeder is studied experimentally. The objective of this paper is to design small wideband antenna for PCS and IMT-2000 service. Experimental results confirm that an impedance bandwidth(VSWR$\leq$2) of 704.7 MHz(35.95 %) is achieved at PCS and IMT-2000 frequency band. The studied antenna can be designed easily for extension of away because it has simple structure.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.9
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• pp.912-918
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• 2003

In this paper, we designed and implemented the dual band monopole antenna for cellular CDMA(Code Division Multiple Access) and IMT-2000(International Mobile Telecommunication 2000) repeater. The antenna was designed by using 3D simulations program, HFSS(High Frequency Structure Simulator). Electrical characteristics were measured by using HP 8720C network analyzer and measured maximum S$\_$11/ was -10.9 dB for all frequency bands of interests in Cellular CDMA and IMT-2000. Simulation results for antenna gain at 859 MHz and 2027.5 MHz were 2.38 dBi and 4.02 dBi respectively with omni directional radiation pattern. The size of implemented antenna is compact and the antenna can be produced in low cost enough for commercialization.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.6
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• pp.882-889
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• 2001

In this paper, the characteristics of u-slot antennas are computed by changing the feed structure, and compared with the measured results. The impedance bandwidths of 13 %(255.1 MHz) and 30.7 %(602.1 MHz) are obtained for probe feed and L-strip feed, respectively. It is known that the designed L-strip feed can be used for increasing the bandwidth of u-slot antennas. In addition, it is shown that the designed L-strip feed u-slot antenna can be used for domestic PCS and IMT-2000 dual band applications.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.40 no.11
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• pp.99-104
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• 2003

We are designed and fabricated the Printed dual monopole antenna with CPW feeder for PCS and IMT2000 band. In this paper il proposed modified dual monopole antenna that is transform conventional monopole antenna to get dual band frequency. The dual monopole antennas had broad bandwidth and omni -directional radiation patterns in construct with conventional monopole antenna. On a monopole operated a stub to other monopole antenna, we could obtain easy an impedance matching. It is increased band width of impedance. The antenna bandwidth is about 150MHz(1.74 ∼1.89〔GHz〕)at 1$^{st}$ resonance frequency and 290MHz(1.95∼2.24GHz) at 2$^{nd}$ resonance frequency on VSWR(equation omitted)1.5 and then we can be got not only 1.75∼1.87〔GHz〕 PCS band but also 1.92∼2.17 〔GHz〕).GHz〕).

• Journal of the Korea Institute of Military Science and Technology
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• v.7 no.2 s.17
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• pp.48-56
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• 2004

This paper presents the GPS receiver's inherent interference effectiveness based on the receiver's internal processing gain. This research is to verify the weakness of the GPS satellite signals and evaluate the receiver's vulnerability in an interference situation. The experiment for the narrow band interference effectiveness for the L1 C/A code GPS receiver has been performed by using the Spirent GSS4765 jamming simulator. After analyzing the experimental result, it is compared with the calculated J/S value of the two different L1 C/A code GPS receivers. By the above result, the narrowband jamming effectiveness of the each jamming source and the jamming margin for the each receiver are to be analyzed in detail. Finally, we could utilize the result to analyze the jamming effectiveness on the GNSS receiver.

• Journal of Advanced Navigation Technology
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• v.19 no.2
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• pp.140-146
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• 2015

Due to the increase in the data traffic for the aeronautical communications, LDACS has been proposed to support the data link in the continental domain. LDACS is defined in two standards of LDACS type-1 and LDACS type-2, which are going to be selected through the intensive comparison. In this paper, we analyzed two types of standards and evaluated their performance for various channel models. Simulation results show that both LDACS type-1 and LDACS type-2 have a good performance in the en-route channel model, while they have a poor performance in the airport channel model. In the comparison results for LDACS type-1 and LDACS type-2, LDACS type-1 shows the better performance of 1dB than LDACS type-2 owing to the stronger channel coding technique.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.5 no.1 s.9
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• pp.65-70
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• 2006

A UHF band RFID passive tag antenna, which can be attached on metallic objects, is proposed. The proposed tag antenna is more insensitive to the size of the metallic object than conventional PIFAs or IFAs. It is constructed on a multi-layer and its size is reduced by using a 'L' slit. Performances of the antenna is analyzed by Ansoft's HFSS and measured using a back-scattering method. The simulated and measured data are obtained with varying the size of metallic object.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.3
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• pp.420-426
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• 2008

In this paper, we present RFID Tag Antenna at 433MHz which can be available for RFID system. The antenna is composed of microstrip type antenna, whose dimension could be reduced by applying fractal theory. Simulated return loss and gain at 433MHz are -20.9dB, -3dBi. But there are some deviation on the point of resonance frequency between simulated and measured results. By modifying the antenna's feeding point, we obtain - l5dB return loss and verify the utility of proposed antenna.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.8
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• pp.549-554
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• 2003

In this paper, we have designed and implemented by a monolithic microwave integrated circuit(MMIC) of a 5.8GHz-band low noise amplifier (LNA) composed of receiver front-end(RFE) in a on-board equipment system for dedicated short range communication. The designed LNA is provided with two active devices, matching circuits, and two drain bias circuits. Operating at a single supply of 3V and a consumption current of 18mA, The gain at center frequency 5.8GHz is 13.4dB, NF is 1.94dB, Input IP3 is -3dBm, S$_{11}$ is -18dB, and S$_{22}$ is -13.3dB. The circuit size is 1.2 $\times$ 0.7 $\textrm{mm}^2$.>.

• Journal of Satellite, Information and Communications
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• v.8 no.4
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• pp.95-99
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• 2013

GPS service is generally being used in the navigation application such as the car navigation and the smart phone. Recently, GPS service continues to increase in the timing application such as the mobile telecommunication network, the smart grid, and the financial network. As GPS signals are sensitive to GPS jamming, it should be monitored and protected. In oder to prevent and minimize the damage caused by GPS jamming, many countries are developing and operating GPS jamming monitoring system. This paper presents the implementation and the test results of the GPS jamming equipment which provides the detection, the direction finding and the location of GPS jamming.