• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.581-586
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• 2002

The development of 2-D radiometer is a new technical challenge for space borne remote sensing area. The Y-type antenna array has been proposed as a most efficient configuration because a large alias free FOV and a small-synthesized beam-width can be achieved compared to L-, T-type under the fixed antenna spacing. New configuration of antenna array, which is called sub-Y type configuration, is proposed to obtain a higher angular resolution than the case of Y-type array in the paper. The sub-Y type array is consisted of basic arrays, which are the Y-type array of four antenna elements. To analyze characteristics of the proposed configuration, the synthesized beam pattern is simulated through simulation. The secondary effect of the sub-Y-type is that the reconstructed image is suffered from the alias effect is appeared around the real target. The ghost targets in the reconstructed image can be reduced by the alias suppression algorithm introduced in this paper. In conclusion, the performance evaluation by use of array factor simulation shows more than 37.5% improvement in average for angular resolution and almost similar performance for temperature resolution.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.2
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• pp.111-118
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• 2003

Notch Antenna is a travelling wave type antenna and can provide multioctave operation in phased arrays that scan over wide angle. In this paper, we designed a wideband E-plane phased array antenna using E-plane waveguide simulator which has a bandwidth of 3 : 1 and a scan volume of $\pm$45$^{\circ}$ in E-plane. We compared impedance of single antenna and infinite array antenna using equivalent circuit modeling. We analyzed full structure of 1$\times$9 phased array antenna and we evaluated active reflection coefficient with variation of beam scan angle through mutual coupling coefficient acquired from simulation and investigated the variation of antenna gain with variation of active element pattern as beam scan angle is varied.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.6
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• pp.636-636
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• 1997

This paper presents the design and fabrication of a shaped-beam array antenna which will be used for a PCS basestation using structure that is coupled to a microstrip line by an aperture on the intervening ground plane. The shaped-beam pattern is obtained by an antenna synthesis method. An array antenna considering the mutual coupling between array elements(patches) and a feeding network are designed by CAD tools. The feeding network is designed by using the Wilkinson power divider to obtain the optimized shaped-beam. The designed results are compared with the measured data.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.5 no.3
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• pp.101-109
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• 2012

Because the installation problem of parabola antenna that is tilted to 45 degree when this antenna is installed at the area of middle latitude, the study on planar antenna in place of parabola antenna is made rapid progess. Especially, The development of the planar antenna for VSAT is needed depending on the increased Ka-band satellite communications. In this paper, in order to meet with these performances, an array antenna consisting of the vertical polarized waveguide longitudinal slots based on the leaky-wave mode of traveling wave antenna is proposed. Especially, for the lower sidelobe level, the design method of the radiation power distribution control using the different slot widths is proposed. An array antenna consisting of 32 leakywave waveguide antennas is showing 35.16 dBi of gain, 2.5 degree of beamwidth at azimuth, below than -30 dB of sidelobe level, 45.8 degree of beam tilt angle in center frequency 30.2 GHz.

• Journal of electromagnetic engineering and science
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• v.18 no.3
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• pp.175-181
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• 2018

The array patterns of a patch array antenna were calculated using an active element pattern (AEP) method that considers ground edge effects. The classical equivalent radiation model of the patch antenna, which is characterized by two radiating slots, was adopted, and the AEPs that include mutual coupling were precisely calculated using full-wave simulated S-parameters. To improve the accuracy of the calculation, the edge diffraction of a ground plane was incorporated into AEP using the uniform geometrical theory of diffraction. The array patterns were then calculated on the basis of the computed AEPs. The array patterns obtained through the conventional AEP approach and the AEP method that takes ground edge effects into account were compared with the findings derived through full-wave simulations conducted using a High Frequency Structure Simulator (HFSS) and FEKO software. Results showed that the array patterns calculated using the proposed AEP method are more accurate than those derived using the conventional AEP technique, especially under a small number of array elements or under increased steering angles.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.2
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• pp.379-382
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• 2017

This paper proposes a $4{\times}4$ broadband phased array antenna using a Left-Handed Transmission Line (LHTL) based phase shifter. The phased array is constructed with sixteen quasi-Yagi antenna elements and the phase shifters, as well as four power dividers. A key component of the system, the LHTL based phase shifter is able to control a phase delay of incident waves linearly and continuously. The fabricated phased array antenna operate for a frequency range of 800 MHz (1.6 GHz~2.4 GHz). The beam scanning range of the $4{\times}4$ array antenna is ${\pm}27^{\circ}$ horizontally and vertically while the antenna gain is maintained with a variation of ${\pm}1.4dBi$.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.3
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• pp.138-145
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• 2008

In this paper, the waveguide slot array antenna which is capable of wide beam steering and dual polarization is designed for an X band synthetic aperture radar. In order to improve the restriction of beam steering range and to remove the butterfly lobes, a typical waveguide slot array antenna has been modified. To implement dual polarization, rod excited waveguide slot elements and ridge waveguide slot elements are alternately arranged. Location of slots, inclination of rod and offset distance of slots are determined on using array characteristic and conductance constant with radiating power on slots. The designed antenna is manufactured and measured with Near-filed measurement method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.3
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• pp.438-444
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• 2015

A new approach to the active phased arrays for the second harmonic generation is presented. Phase variation between the second harmonic oscillators by the mutual synchronization is analyzed theoretically. In this coupling, the active antenna consists of the FET oscillator which plays two roles in fundamental oscillation and frequency multiplying, and the patch antenna resonated at the second harmonic frequency. The radiated second harmonic wave was scanned by varying the free-running oscillation frequencies of the active antennas. In the experiment using the 2-elements array and the 4-elements array, the radiated beam of the second harmonic wave was scanned more widely compared with the case of the fundamental wave radiation.

• Journal of Satellite, Information and Communications
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• v.10 no.4
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• pp.46-51
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• 2015

In this paper, I design a linear array antenna simulator for anti-jamming GPS systems and perform various performance analysis by simulation. First, I generate simulated transmission signals through the analysis of GPS satellite signal structure, and analyze SNR(Signal to Noise power Ratio) performance of linear array antenna according to number of arrays under noise environments. In addition, I analyze the performance of the anti-jamming beam pattern using MMSE(Minimum Mean Square Error) signal processing method, and also analyze the anti-jamming performance considering antenna calibration problem when there are different delays between arrays.

• Journal of the Korea Institute of Military Science and Technology
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• v.6 no.3
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• pp.113-121
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• 2003

In this paper, the transmit antenna for the space feeder used for the phased array antennas is investigated. The multi-aperture horn antenna is proposed as the transmit antenna and the characteristics are verified with the Matlab coding, HFSS of Ansoft Corp., and MWS of CST Corp., The E-plane and H-plane beam patterns of the multi-aperture horn antenna are nearly symmetrical and the sidelobe level of the I-plane beam pattern is lower than that the of general pyramidal horn antenna. The fabricated multi-aperture horn antenna is measured using the near-field measurement system. The measured results show good agreement with the simulated ones.