• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.42 no.7
• /
• pp.567-575
• /
• 2014

This paper suggests an installation procedure of a smart skin prototype into an aircraft, flight demonstration test procedures and test results. Four communication and navigation antennas are embedded into one Conformal Load-bearing Antenna Structure(CLAS). Log periodic patch type antenna was designed as a multi-band antenna to cover four antenna frequency bands. The requirements of CLAS were verified by ground tests before aircraft installation. A CLAS speed-brake was installed into KT-1 aircraft and performances of dual antennas were verified as multi-antenna tests on the ground. Electromagnetic compatibility tests were conducted to check compatibility between the CLAS and all existing equipments. Flight demonstration tests were conducted by one sortie of flight test for one antenna. The activeness and continuity of communication and navigation signal during the flight, null area of antenna signal along the circling flight were monitored. The embedded antennas worked better than expected during four sorties of flight tests.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.3
• /
• pp.497-502
• /
• 2014

In this paper, a design method for a broadband planar dipole antenna for terrestrial digital television (DTV) reception is studied. The dipole is modified to half bow-tie type for size reduction. The balun between feeding microstrip line and coplanar strip (CPS) line is implemented with a rectangular patch inserted along the center of the CPS line. The proposed antenna is the structure of dual resonances, one is due to the dipole and the other is due to the CPS line attached by the balun. The effects of various geometrical parameters on the antenna performance are examined, and the antenna is designed for terrestrial DTV band (470-806 MHz). The prototype antenna is fabricated on an FR4 substrate with a size of $95mm{\times}178mm$, and tested experimentally to verify the results of this study.

• 한국정보통신설비학회:학술대회논문집
• /
• 2004.08a
• /
• pp.377-381
• /
• 2004

안테나를 소형화시키기 위해 많은 노력을 들여왔다. 모노폴 안테나의 크기를 줄이기 위해 많은 연구가 있어왔고 그 중 모노폴 끝에 원반 모양의 패치를 붙인 것이 top-hat 패치 안테나이다. 그리고 다른 대표적인 방법 중의 하나가 PIFA(Planar inverted-F antenna) 구조의 안테나이다. 이 둘을 이용해서 좀 더 작은 크기의 안테나를 구현할 수 있고 안테나 구조를 적절히 변형하여 이중 공진을 일으킬 수 있다. 본 논문에서는 패치에 슬롯을 주어 전류의 흐름을 변환시켜 이중 공진을 일으킬 수 있는 구조를 제안하였다. 무엇보다도 중요한 점은 이 안테나의 몇 가지 요소를 변화시킴으로써 공진주파수를 원하는 대로 바꿀 수 있다는 것이다.

• Proceedings of KOSOMES biannual meeting
• /
• 2017.04a
• /
• pp.150-150
• /
• 2017

• Proceedings of the KAIS Fall Conference
• /
• 2006.11a
• /
• pp.195-198
• /
• 2006

본 논문에서는 휴대용 무선통신기기에 장착해서 사용가능한 이중대역(RFID(908.5-914), PCS) 소형 내장형 RFID 안테나를 설계하였다. 안테나 디자인은 PIFA(Planar Inverted-F Antenna)이며 기존 안테나 아래쪽에 접지와 연결된 패턴을 추가하여 결합성분을 유도하여 소형화 하였으며 표면 전류분포를 분산시켜 SAR를 개선하는 방법을 제시 하였다. 시뮬레이션 결과에 따라 안테나가 실제 제작 되고 측정되었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.25 no.12
• /
• pp.949-954
• /
• 2012

The K-PCS and W-CDMA dual band dielectric duplexer and bandpass filters have been designed and fabricated. The dual band duplexer consists of the separate monoblock K-PCS and W-CDMA duplexers using common antenna port. The coupling capacitance and I/O impedance matching have been designed to minimize the cross interference between the bands. Isolations of crosspoint between Tx and Rx in K-PCS and W-CDMA dualband were about 47 dB and 100 dB, respectively. On the other hand, isolations of Tx and Rx in K-PCS and W-CDMA were about 66 dB and 65 dB, respectively. The difference between 47 dB and 100 dB originated from the different center frequencies in Tx and Rx of K-PCS and W-CDMA bands. The coupling capacitance of the bandwidth, I/O capacitance of I/O matching and impedance matching, and various capacitances were important role to fabricate the dielectric duplexer and bandpass filters.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.7 no.8
• /
• pp.1604-1611
• /
• 2003

For dual­band operation, it can be done by loading two pair of slits in the equilateral­triangular patch, one embeded close to the side edges of the patch and the other inserted at the bottom edge of the patch. The frequency ratio of the two operating frequencies can be tuned by varing the positions and lengths of the inserted slots at the bottom edge of the patch. While the calculated frequency ratio of the antenna by Ensemble 5.0 is $1.66 ({f_10}=1.928GHz, {f_20}=3.2GHz)$, the measured one is 2.04 $({f_10}=1.6806 GHz, {f_20}=3.435 GHz)$. The error in the frequency ratio is due on the fabrication dimension and feeding position error as well as on the permittivity dispersion effect.

• Proceedings of the KSRS Conference
• /
• 2009.03a
• /
• pp.40-45
• /
• 2009

본 연구에서는 기후 등의 영향을 받지 않고 레이더 산란 측정을 할 수 있는 X-band antenna 기반의 자동관측 시스템을 이용하여 벼 생육시기에 따른 후방산란계수와 벼 생육인자와의 관계를 분석하여 후방산란계수를 이용한 벼 생육인자를 추정한 것을 목적으로 하였다. 2008년도 국립농업과학원 시험포장 ($37^{\circ}$15'28.0"N, $126^{\circ}$59'21.5"E)에서 추청벼를 대상으로 생육시기별 후방산란계수를 관측하였는데 모든 편파별 후방산란계수가 벼 유수형성기 (7월 말경)까지 증가하다가 그 후 감소하다가 수확기가 가까워지는 9월 중순이후 다시 증가하는 dual-peak 현상을 보였고 특히 W-편파의 경우 9월 초순부터 후방산란계수 증가가 다른 polarization에 비해 크게 나타났다. 후방산란계수와 작물생육인자와의 관계를 분석한 결과 고주파수인 X-band는 상대적으로 바이오메스, 엽 면적지수와의 상관이 낮게 나타났지만 이삭 건물중은 VV-편파 후방산란계수와 상관관계를 보였다. 이삭 건물중과 상관관계가 높게 나타난 X-band의 W-편파 후방산란계수를 이용하여 수확기 이삭 건물중을 추정하였는데 VV-편파 후방산란계수와 이삭 건물중과는 결정계수 $(R^2)$가 0.85이었고, 이삭 건물중 실측값과 추정값을 비교해 본 결과 1:1 line에 근접하게 분포하였다 ($R^2$=0.85).

• Proceedings of the IEEK Conference
• /
• 2002.07b
• /
• pp.715-718
• /
• 2002

TX/RX dual microstrip 1$\times$8 sub-array antennas are designed, fabricated, and measured for a wideband array antennas in communications. They have a Right Handed Circular Polarization (RHCP) for TX from 7.9 to 8.4 GHz and Left Handed Circular Polarization (LHCP) for RX from 7.25 to 7.75 GHz. Two stacked patches are used for a wideband characteristics and cornertruncated square patches are adopted for a circular polarization. To enhance bandwidth characteristics of a circular polarization, 1$\times$2 sequential rotation arrays are applied. From the measured results, 1$\times$8 microstrip sub-array antennas have a good agreement with those of the simulation. Therefore the sub-array antennas are applicable to satellite communication antennas, active phased array antennas, and radiators in other antennas.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.10
• /
• pp.1150-1156
• /
• 2007

In this paper, two novel subsurface antennas for remote management of underground facilities using PCS and cellular wireless network are proposed. The proposed subsurface antenna is a dual band circular patch which is inserted and molded for the protection of the antenna into a metal such as a manhole cover. The antenna is designed considering the resonant frequency shift of the antenna due to the insertion and molding. The measured return loss and receiving power of the fabricated antenna comparison with a dipole shows that two proposed subsurface antenna can be used for remote management of underground facilities using PCS and cellular systems.