• The Journal of the Korea Contents Association
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• v.6 no.2
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• pp.99-104
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• 2006

This paper proposed a method to design the offset slotted rectangular microstrip patch antenna which can be used for GPS antenna. The multi-port connection method and the desegmentation technique had been used to analyze !he characteristics of this antenna. To reduce a size of this antenna, a dielectric substrate with a high permittivity($\varepsilon_{\gamma}$=10.2) was used and a offset rectangular slot was inserted in the microstrip patch antenna. The dimension of a manufactured antenna is $20\times30\times1.27$[mm]. Accordingly this small antenna can be used directly GPS antenna or cellular phone.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.8B
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• pp.1348-1356
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• 2000

In this paper, we proposed a trellis coded Multi-Carrier CDMA 16 QAM system with multiple transmit/receive antenna diversity technique, which is simple and suitable for indoor wireless communications. The proposed multiple transmit/receive antenna diversity technique is that the transmitter sends a trellis coded Multi-Carrier CDMA 16 QAM signal from multiple transmitting antennas with intentional time delays, which makes a receiver possible to distinguish and combine the signals from different antennas. In wireless indoor communication system, if we allow the increase of the complexity of the system, it is also possible to achieve additional diversity gain in the performance with the combination of the proposed technique and the conventional receiving antenna diversity. Furthermore, we have found that the proposed trellis coded Multi-Carrier CDMA 16 QAM system, which employs multiple transmit/receive antenna, is less sensitive to the multiple user interference and fading than conventional receiving antenna diversity systems.

• Journal of the Institute of Convergence Signal Processing
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• v.16 no.4
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• pp.156-161
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• 2015

In this paper, a dual-polarized multi-band multi-layer antenna for a vehicle, which operates in the GPS, bluetooth, and DSRC bands, was implemented. The antenna was designed as a multi-layer structure, and a FR4-epoxy substrate with =4.4 and =1.6mm was used. GPS and DSRC antennas have circular polarized characteristics, and a single probe feeding method was applied. Simulated results by Ansys HFSS v11 was compared with the measured ones. The size of the optimally designed antenna is $67mm{\times}67mm{\times}4.8mm$, -10dB bandwidth of the anatenna was measured to be 820MHz, 127MHz, and 862MHz in each band, and 3dB AR bandwidth of the antenna was simulated to be 19MHz and 110MHz in GPS and DSRC bands. The results confirmed that suggested system satisfies the system requirements.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.5
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• pp.501-505
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• 2008

In this paper, we present a multi-turn circular loop antenna for portable terrestrial DMB. In order to satisfy the two contradictory requirements of small antenna size and high receiving capability, the proposed antenna's diameter and turns are fixed to be 4 mm and 80 turns, respectively and its quality factor $\mathcal{Q}$ is set 1 in order to have high transfer function. The fabricated antenna length is 30 mm as small and its measured gain is -15 dBd. The antenna receiving power is verified by measurement very comparable with the receiving power of a commercial terrestrial DMB monopole antenna of length 190 mm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.8
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• pp.2763-2782
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• 2014

In this paper, a generalized likelihood ratio test (GLRT) is proposed for cyclostationary multi-antenna spectrum sensing in cognitive radio systems, which takes into account the cyclic autocorrelations obtained from all the receiver antennas and the cyclic cross-correlations obtained from all pairs of receiver antennas. The proposed GLRT employs a different hypotheses problem formulation and a different asymptotic covariance estimation method, which are proved to be more suitable for multi-antenna systems than those employed by the $Dandawat{\acute{e}}$-Giannakis algorithm. Moreover, we derive the asymptotic distributions of the proposed test statistics, and prove the constant false alarm rate property of the proposed algorithm. Extensive simulations are conducted, showing that the proposed GLRT can achieve better detection performance than the $Dandawat{\acute{e}}$-Giannakis algorithm and its extension for multi-antenna cases.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.254-257
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• 2003

본 논문에서는 휴대폰에 사용되는 Multi-band 용 helical antenna 의 radiation pattern 을 체적화하기 위한 방법을 제안하고자 하였다. 일반적으로 GSM 휴대폰에 사용되는 안테나는 GSM, DCS 의 dual band 인 경우가 다수이며 추세에 따라 요즘은 PCS 등을 포함한 triple band 의 안테나가 많이 선호되고 있다. 이러한 multi band antenna 의 radiation pattern 에 영향을 미치는 변수로 본 논문에서는 ground 의 length 와 width 그리고 폴더쪽에 사용되는 LCD 의 ground 와 폴더쪽 기구물에 사용된 EMI spray 등의 변화를 통해 pattern 의 변화를 알아보고 이러한 변수를 조절하여 radiation pattern을 최적화하는 방법에 관하여 논하였다.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.265-270
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• 2005

In this paper, four-element MIMO(Multi-Input Multi-Output) antenna operating at 5.2GHz and 5.8GHz is proposed. Each antenna element is fabricated by using inverted-L type and the isolation characteristic among antenna elements is adjusted by the distance between radiation element and ground. The designed array antenna has the impedance bandwidth at 5.15$\sim$5.35 and 5.725$\sim$5.825GHz for VSWR$\leq$3 and the isolation characteristic less than -20dB at same frequency.

• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.419-422
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• 2007

This paper, designed UWB elliptical slot antenna and analysis based on the distribution of the electromagnetic fields pattern and resonant mode of designed antenna is presented. Designed antenna is fabricated on FR4 substrate with thickness of 1.524mm and relative dielectric constant 4.4. The measured bandwidth of $3.6GHz{\sim}20GHz$ for VSWR<2. Through the field pattern and resonant mode analysis that the slot antenna operates on a series of the multi-pole radiation based on TE modes matched to system impedance. And the perfect magnetic wall is along the axis of symmetry on the y-z plane. This result gives us an easier method to design the similar antennas, which is the impedance matching to the system impedance after once constructing a proper structure with a series of multi-mode resonances.

• Journal of Industrial Technology
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• v.27 no.B
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• pp.129-135
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• 2007

In this paper, an modal analysis based on the distribution of the electromagnetic fields on the UWB elliptical patch-slot antenna is presented. We designed the UWB antenna by iterating the dimensional parameters of the antenna as the traditional design method. Then the antenna was carefully analyzed using 3D E-M simulator. The result of the analysis shows that the slot antenna operates on a series of the multi-pole radiations based on TE modes matched to the system impedance. This result gives us an easier method to design the similar antennas, which is the impedance matching to the system impedance after once constructing a proper structure with a series of multi-mode resonances.

• IEMEK Journal of Embedded Systems and Applications
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• v.8 no.2
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• pp.95-102
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• 2013

In this paper, we have studied the performance of the AOA (Angle of Arrival) in multi-antenna systems for LBS (Location Based Services) and we also analyzed the performance of the AOA in SISO (Single Input Single Output) in multipath environments and their differences. The adequacy of AOA positioning in new communication environments was determined. Currently used positioning methods in 3G communication environment has been developed based on SISO. However, the accuracy of SISO-based TOA (Time of Arrival), TDOA (Time Difference of Arrival), AOA positioning techniques degraded in multipath environments. The communication system will be changed and developed. According to enhanced positioning techniques are required. Using antenna characteristics and the phase difference between antennas of LTE-Advanced standard's key technique MIMO system AOA positioning, and SISO based AOA positioning performance were analyzed. We found that AOA technique potential for use based on Multiple antenna systems by computer simulations.