• Journal of electromagnetic engineering and science
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• v.4 no.4
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• pp.150-155
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• 2004

Universal design equations are presented for the H-plane T-junction power divider with a circular conducting post in a rectangular waveguide. For a given operating frequency and power split ratio, the post offset from the T-junction center line, the distance between the post and the waveguide wall, and the post diameter can be adjusted to obtain a minimum reflection at the input waveguide. Optimum values of the post offset are given in terms of the normalized frequency and the power split ratio. Corresponding values of the post diameter and the distance of the post from the waveguide wall are given in terms of the normalized frequency and the post offset.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.2
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• pp.151-158
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• 2012

This paper proposes a H-plane 8-way rectangular waveguide power divider using Y-junction. A general N-way power divider can be composed of multi-stage T-junctions. However, if the distances of output ports are close, the matching characteristic is not improved by using only T-junctions because of space limitation. In this case, since other types of 3-port junctions should be used to final output stage, Y-junctions are used with T-junctions in this paper. The proposed Y-junction uses the tapered-line impedance transformer and inductive irises to improve impedance matching characteristic. The 8-way power divider using Y-junction is fabricated and measured. The measured return loss and insertion loss from input port to output port are -30.8 dB and -9.3 dB at operating frequency, respectively. The measured maximum phase difference is about $1^{\circ}$. Therefore, the proposed power divider will be useful to apply to various microwave systems, which need to divide the input power equally, such as feed networks for array antennas.

• Journal of electromagnetic engineering and science
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• v.10 no.3
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• pp.171-174
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• 2010

In the paper, a printed dual-dipole array antenna is presented. A 4-way planar SIW power divider is adopted for feeding the array antenna. The dual-dipole is adopted as radiation elements which greatly improves the impedance band. The measured bandwidth larger than 31 % for VSWR$\leq$1.5 operating near 14 GHz is achieved and in agreement with the simulated results. The radiation E-plane and H-plane radiation pattern is presented in the paper. The radiation gain is also presented in the paper.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.43-55
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• 2013

In this paper, we propose a cylindrical active phased array antenna of Beam Steering Characteristics in the horizontal plane(H-plane) and vertical plane(E-Plane) on the cylinder form array structure. We design the bent dipole antenna of the cylindrical array structure adapted excellent mutual-coupling characteristics, designed and manufactured the cylindrical array antennas and power combiner/divider unit for power dividing and combining on the antenna. The radiating elements array spacing of Cylindrical array antenna were determined to avoid grating lobes at half power beam steering. Beam steering of the antenna was implemented with 6-bit phase shifter in the transceiver and have been designed based on the characteristics the antenna beam steering at -24 degrees to 24 degrees horizontal, vertical 0 degrees to 36 degrees beam steering. A cylindrical active phased array antenna that produced for verification the performance of the antenna are measured radiation characteristics in accordance with beam steering at L-Band.

• Proceedings of the Optical Society of Korea Conference
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• 1989.02a
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• pp.152-156
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• 1989

Parameters of a microstrip patch antenna such as the resonant frequency, radiation conductance, and the bandwidth are calculated. The rectangular microstrip patch antenna fed by a microstrip transmission line is fabricated and its resonant frequency, radiation pattern, and input voltage standing wave ratio are measured. The measured resonant frequency for 13.0mm$\times$9.7mm copper clad woven PTFE/glass laminate plate is 9.06Ghz, where the calculative is 9.00Ghz. And the measured vswr shows that the bandwidth of the antenna is 225MHz for vswr less then 2.0 which the calculated quality factor of the patch gives the bandwidth OF 280ghZ. The measured radiation pattern for 5 element as well as 4 element patch array shows less then 4dB deviation in the first side lobes from the designed values for both E and H plane pattern. This diviation is believed to be the power division errors of the power divider.

• Journal of electromagnetic engineering and science
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• v.13 no.3
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• pp.178-185
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• 2013

This paper introduces a high-efficiency, high-gain, broadband quasi-Yagi antenna, and its four-element array for use in 60-GHz wireless communications. The antenna was fed by a microstrip-to-slotline transition consisting of a curved microstripline and a circular slot to allow broadband characteristics. A corrugated ground plane was employed as a reflector to improve the gains in the low-frequency region of the operation bandwidth, and consequently, to reduce variation. The single antenna yielded an impedance bandwidth of 49 to 69 GHz for $|S_{11}|$ <-10dB and a gain of >12.0 dBi while the array exhibited a bandwidth of 52 to 68 GHz and a gain greater than 15.0 dBi. Both proposed designs had small gain variations (${\pm}0.5$ dBi) and high radiation efficiency (>95%) in the 60-GHz bands. The features of the proposed antenna were validated by designing, fabricating, and testing a scaled-up configuration of the single antenna at the 15-GHz band. The measurements resulted in an impedance bandwidth of 13.0 to 17.5 GHz for $|S_{11}|$ <-10dB, a gain of 10.1 to 13.2 dBi, and radiation efficiency in excess of 88% within this bandwidth. Additionally, the 15-GHz antenna yielded quite symmetric radiation profiles in both E- and H-planes, with a high front-to-back ratio.