• Title/Summary/Keyword: Noise antenna

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Performance Analysis of PN Code Acquisition with Antenna Diversity (안테나 다이버시티를 이용한 PN 코드 획득 성능 분석)

  • Seo, Sung Il
    • Journal of Satellite, Information and Communications
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    • v.12 no.1
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    • pp.120-124
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    • 2017
  • In this paper, effect of antenna diversity on pseudorandom noise (PN) code acquisition performance is analyzed and simulated for a direct sequence/code division multiple access (DS/CDMA) overlay system where a CDMA user and a narrowband user coexist in the same frequency band. From the simulation results, it is shown that the antenna diversity is very effective in improving the PN acquisition performance. The results of this paper can be applied to design of synchronization scheme for a DS/CDMA overlay environment.

Micro-vibration Isolation Performance of X-band Antenna using Blade Gear (블레이드 기어를 적용한 X-밴드 안테나 미소진동 절연성능)

  • Jeon, Su-Hyeon;Kwon, Seong-Cheol;Kim, Tae-Hong;Kim, Yong-Hoon;Oh, Hyun-Ung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.893-899
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    • 2014
  • X-band antenna has been widely used to effectively transmit the high resolution image data from the observation satellite to the ground station. To achieve above mission, X-band antenna is mainly composed of the 2-axis gimbal system using stepping motors and gears. However, the micro-vibration induced by the stepping motor actuation and the imperfect gear teeth alignment during this on-orbit operation is the main source of image quality degradation. In this paper, X-band antenna combined with a blade gear for micro-vibration isolation was suggested and investigated. The structural safety of the blade gear with low rotational stiffness was confirmed by structure analysis based on the derived torque budget. The isolation performance of the X-band antenna with the blade gear was verified through micro-vibration measurement test using the dedicated micro-vibration measurement device proposed in this study.

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Design of Active Antenna for 5.5GHz Local Wireless Communication System (5.5GHz 근거리 무선통신용 능동안테나 설계)

  • Kim Kab-ki;Choi Chung-yun;Kim Chol-soo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.7
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    • pp.1558-1564
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    • 2004
  • This paper shows the design of Active antenna which appled to 5.5GHz RF module for local wireless communication system. The LNA, which was designed Super low noise HJ FET of NE3210S01, is used to obtain a good noise figure characteristics. And the microstrip patch antenna was designed to obtain omnidirectional antenna characteristics. The measured LNA gain is 15 dB, input & output return loss is under -20 dB and VSWR under 1.5. The Single microstrip patch antenna input return loss is under -29 45, VSWR under 1.2.

Design of Active Antenna for Wireless LAN (무선랜용 능동안테나 설계)

  • Kim, Pyoung-Gug;Jung, Sang-Woon;Boo, Jong-Bae;Lee, Yeong-Su;Kim, Kab-Ki
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.1
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    • pp.265-269
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    • 2005
  • In this paper shows the Designed active antenna for wireless LAN that is consisted of 5.5GHz band local LNA and Microstrip Patch Antenna. LNA improved noise special quality using NEC company's NE3210S01 and Microstrip Patch Antenna designed to have omnidirectional characteristic. Designed Microstrip Patch Antenna expressed omnidirectional characteristic special quality having gains of about 8.3dBi. LNA gains 15dB, noise index showed special quality under 1 dB.

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Ka-band Compact AESA Antenna Unit Design for Seeker

  • Bongmo Kang;Ikjong Bae;Jaesub Han;Youngwan. Kim;Jaehyun Shin;Jihan Joo;Seonghyun Ryu
    • International Journal of Internet, Broadcasting and Communication
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    • v.16 no.1
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    • pp.330-338
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    • 2024
  • In this paper, a Ka-band high-output active phased array antenna device applicable to small radars and seekers was designed, and the improved performance was studied. The radiation device assembly consists of 1x8 arrangements, and the step flared notch antenna type. It shows low active reflection loss characteristics in broadband, and low loss characteristics by applying the air-strip feeding structure, and is designed to enable beam steering up to 45 degrees. The TRM(transmit receive module) output power is more than 2.0W per channel using GaN HPA in the transmitting path, and satisfies more than 25.0 dB gain and less than 6.0 dB noise figure in the receiving path. Accordingly, the Effective Isotropically Radiated Power(EIRP) of the antenna unit shows the performance of 0.00 dB or more and the receive gain-to-noise temperature ratio(G/T) of 0.00 dB/k or more. For demonstration, we have designed aforementioned planar array antenna which consists of 64 radiating elements having a size within 130 mm x 130 mm x 300 mm and weight of less than 4.9 kg..

On the Utilization of Polarization Dependency Acquired by an Intentionally Misaligned Antenna Array for Mitigation of GPS Jammers

  • Park, Kwansik;Seo, Jiwon
    • Journal of Positioning, Navigation, and Timing
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    • v.10 no.4
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    • pp.291-296
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    • 2021
  • Recently, the dual-polarized antenna array has drawn attention due to the dependency of its signal processing gain on the signal polarization. Even though this polarization dependency makes it possible to mitigate a non-right-hand circularly polarized (non-RHCP) jamming signal from the same direction as a GPS signal, the dual-polarized antennas are not yet widely used for various applications. This study suggests a method that can acquire the polarization dependency of the signal-processing gain by intentionally misaligning antenna elements in a single-polarized antenna array. The simulation results show that the proposed method can successfully mitigate a non-RHCP jammer from the same direction as a GPS signal as if a dual-polarized antenna array does and provide comparable signal-to-jammer-plus-noise ratio (SJNR) performance with a completely aligned single-polarized antenna array and a dual-polarized antenna array.

Studies on IF noise caused by transmitter signal leakages of the W-band homodyne FMCW radar with a single antenna configuration (단일 안테나를 사용하는 W-대역 호모다인 FMCW 레이더의 누설신호에 의한 IF 잡음에 관한 연구)

  • Park Jung-Dong;Kim Wan-Joo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.7 s.337
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    • pp.49-56
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    • 2005
  • In this paper, we describe a solution to improve the effects of the transmitter leakage signals on the frequency modulated continuous wave (FMCW) radar with a single antenna configuration. We analyze characteristics of the IF noise caused by insufficient isolation between transmitter and receiver. The magnitude of the intermediate frequency (IF) noise from a front-end can be reduced by matching the LO signal delay time with that of the largest leakage source. Because the IF noise has periodic singularities at nT$_{m}$/2, t=0,1,2$\cdots$, we find that spectrum of the IF noise due to the leakage signals is very similar to that of the VCO moduation signal except low frequency elements in the vicinity of DC. Based on the studies, we fabricated a W-band homodyne FMCW radar sensor and verified the proposed solution. The results are applicable to design of the homodyne FMCW radar with a single antenna configuration.

Implementation of Small Active Antenna for GPS/GLONASS Receiving (GPS/GLONASS 수신용 소형 액티브 안테나의 구현)

  • Kang, Sang-Won
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.15 no.2
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    • pp.175-180
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    • 2015
  • In this paper, GPS / GLONASS receiving a small active antenna is proposed. A microstrip patch antenna which supports dual-band (GPS and GLONASS) was optimized. The antenna size is $13{\times}13{\times}3.6mm$. The jig was changed to confirm the proposed antenna characteristic size, was adjusted to feed gap of the patch antenna, it was confirmed by change in LNA shield case or not. The antenna jig size is $65.6{\times}13{\times}0.8mm$. The maximum gain of the GPS band is 3.78dBi, the maximum gain of the GLONASS bands is 4dBi. To amplify the Satellite reception signal level, one-stage low noise amplifier(LNA) was designed. The LNA chip was using the BGA715 N7, the LNA gain is 19.9dB. The utilization possibility of the GPS / GLONASS receiving a small active antenna could be confirmed according to compare and analyze the simulation and measurement data.

Prediction of Noise Power Disturbance from Antenna to Transmission Line System (안테나로부터 인접 전송선로에 전달되는 노이즈 전력 예측)

  • Ryu, Soojung;Jeon, Jiwoon;Kim, Kwangho;Jo, Jeongmin;Lee, Seungbae;Kim, SoYoung;Nah, Wansoo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.25 no.11
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    • pp.1172-1182
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    • 2014
  • In these days, many kinds of goods are more light and more integrated. As frequency range of mobile applications have increased to improve performance of antenna furthermore, EMI(ElectroMagnetic Interference) problem has frequently caused by disturbance of antenna in device which aggravates other circuit. This paper proposes a technique for the prediction of noise power to the transmission line from antenna located near the line. Although noise power transferred to transmission line is varied by source impedance of antenna and load impedance of transmission line basically, the power magnitude can be presented in a square form of S-parameter between antenna and transmission line due to small variation of transferred power. For this reason, we can use the index expressed the transferred power varied along geometrical shapes of transmission line. As a result, big difference is occurred along location of antenna especially the bended line. And this such experiment is correspond with simulation, these results have meaning physically considering electromagnetic field distribution in near and far field. HFSS of Ansys and CPW with ground is used in this paper.

Performance of a Rectangular Smart Antenna in CDMA Basestation (CDMA 기지국에 설치된 평면 스마트 안테나의 성능 고찰)

  • Hong, Young-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.3C
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    • pp.323-330
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    • 2007
  • Performance indicators such as output SNR, SIR, SINR for rectangular smart antennas in CDMA basestations have been derived. Simulations have been carried out to find the rectangular smart antenna performance while varying the input SNR, number of antenna elements, and the interferers' spatial distributions. Simplified Conjugate Gradient Method was chosen as the underlying beam forming algorithm. It has been shown that the performance of a rectangular smart antenna is similar to that of the linear one having the same number of elements when the interferers are randomly distributed over the whole azimuth angle range.