• International Journal of Computer Science & Network Security
• /
• 제24권2호
• /
• pp.53-58
• /
• 2024

This paper presents a novel miniaturized 3-D cubic antenna for use in wireless sensor network (WSN) application. The geometry of this antenna is designed as a cube including a meander dipole antenna. A truly omnidirectional pattern is produced by this antenna in both E-plane and H-plane, which allows for non-intermittent communication that is orientation independent. The operating frequency lies in the ISM band (centered in 2.45 GHz). The dimensions of this ultra-compact cubic antenna are 1.25*1.12*1cm3 which features a length dimension λ/11. The coefficient which presents the overall antenna structure is Ka=0.44. The cubic shape of the antenna is allowing for smart packaging, as sensor equipment may be easily integrated into the cube hallow interior. The major constraint of WSN is the energy consumption. The power consumption of radio communication unit is relatively high. So it is necessary to design an antenna which improves the energy efficiency. The parameters considered in this work are the resonant frequency, return loss, efficiency, bandwidth, radiation pattern, gain and the electromagnetic field of the proposed antenna. The specificity of this geometry is that its size is relatively small with an excellent gain and efficiency compared to previously structures (reported in the literature). All results of the simulations were performed by CST Microwave Studio simulation software and validated with HFSS. We used Advanced Design System (ADS) to validate the equivalent scheme of our conception. Input here the part of summary.

• 전자공학회논문지A
• /
• 제32A권12호
• /
• pp.36-47
• /
• 1995

The main purpose of this paper is to determine a new focal point and field distribution due to the shape deformation of reflector antenna by numerical method such as geometrical optics and the aperture field method. It is shown the 4 types deformations to be added into original shape of parabola antenna and offset antenna: linear, quadratic, cubic and hybrid distortion. These results can be applied to deformed reflector antenna in order to fit a focal point and radiation pattern.

• 한국통신학회논문지
• /
• 제11권4호
• /
• pp.241-250
• /
• 1986

안테나 해석 및 설계에 있어 전류분포는 그 기본을 이루고 있다. 본 연구에서는 가는 도체를 평면상에 감은 나선형 산란체에 평면파가 입사한 경우의 나선형 도체의 전류분포를 적분방정식을 세워서 구하는 방법을 제시하고, 나선형 산란체의 길이(회전수)와 입사파의 입사각을 바꾼 경우의 전류분포를 계산한 결과를 제시하였다 수치 해석으로는 기저 함수로 Cubic B-Spline 함수를 이용한 Point matching 방법을 적용하였다.

• 천문학회보
• /
• 제41권2호
• /
• pp.66.2-66.2
• /
• 2016

KASI and NAOJ are making collaborating efforts to implement faster mapping capability into the new 275-500 GHz Atacama Submillimeter Telescope Experiment focal plane array (FPA). Feed horn antenna is one of critical parts of the FPA. Required fractional bandwidth is almost 60 % while that of traditional conical horn is less than 50 %. Therefore, to achieve this wideband performance, we adopted a horn of which the corrugation depths have a longitudinal profile. A profiled horn has features not only of wide bandwidth but also of shorter length compared to a linear-tapered corrugated horn, and lower cost fabrication with less error can be feasible. In our design process the flare region is represented by a cubic splined curve with several parameters. Parameters of the flare region and each dimension of the throat region are optimized by a differential evolution algorithm to keep >20 dB return loss and >30 dB maximum cross-polarization level over the operation bandwidth. To evaluate RF performance of the horn generated by the optimizer, we used a commercial mode matching software, WASP-NET. Also, Gaussian beam (GB) masks to far fields were applied to give better GB behavior over frequencies. The optimized design shows >23 dB return loss and >33 dB maximum cross-polarization level over the whole band. Gaussicity of the horn is over 96.6 %. The length of the horn is 12.5 mm which is just 57 % of the ALMA band 8 feed horn (21.96 mm).

• 한국전자파학회논문지
• /
• 제14권11호
• /
• pp.1113-1120
• /
• 2003

향후 CDMA(Code Division Multiple Access) 디지털 셀룰러 이동통신망에서는 안테나와 RF(Radio Frequency) 송ㆍ수신기만을 갖춘 다수의 소형 기지국들을 광섬유를 이용하여 중앙국으로 연결시키는 SCM(Subcarrier Multiplexing) 광링크 시스템의 수요가 많이 예상된다. 본 논문에서는 CDMA RF 신호전송을 위한 SCM 광링크 시스템의 성능분석을 위하여 Mach-Zehnder변조기(MZM)의 전달함수를 입력신호가 3제곱이 되어 출력되는 비선형으로 모델링 하였다. 그리고 페이딩 채널 영향으로 다중경로 신호성분을 가지고 소형 기지국에 수신되는 여러 다중 가입자 CDMA 신호들이 MZM을 통과한 후 복조되는 과정에서 생기는 다중접속 간섭신호를 유도하여 성능분석을 하고 레이크 수신기를 이용하여 성능개선을 하였다.