• Journal of electromagnetic engineering and science
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• v.2 no.2
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• pp.65-67
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• 2002

An approximate, numerically-efficient solution for a microstrip T-junction is discussed. The microstrip T-junction is modeled as a rectangular waveguide with top/bottom electric walls and side magnetic walls. Comparisons of our solution with others show favorable agreements.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1180-1185
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• 2009

In this paper, the Low Pass Filter (LPF) using the equivalent circuit of T-junction microstrip line is proposed. And we derived the formulas for lumped-elements of the equivalent circuit of T-junction microstrip line to solve the frequency shift characteristic. T-junction microstrip line is de-embedded by Electromagnetic simulation tool and exact lumped element value of T-junction microstrip line is calculated by the equation of Z-parameter. We can get excellent agreement between lumped-element LPF frequency response and transmission line LPF frequency response.

• The Journal of Korean Institute of Information Technology
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• v.16 no.11
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• pp.77-84
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• 2018

In this paper, the circular polarization microstrip patch antenna using the T-junction power divider is proposed. The operating frequency of the proposed antenna is ISM band of 2.4GHz and the circular polarization is induced by feeding a phase difference of $90^{\circ}$ in two edges. The structure of the antenna consists of a general patch and a T-junction power divider. Furthermore, to optimize the proposed antenna, it is analyzed the reflection coefficient, the axial ration and the radiation pattern. The impedance bandwidth of the antenna is observed to be 40MHz within a range of 2.39 to 2.43GHz, similarly, the axial ratio bandwidth is observed having the bandwidth of about 12MHz in 2.398 to 2.410GHz range. The radiation pattern of the antenna is seen to be right circular polarization. Furthermore, the gain of the antenna is observed to be 2.04 and 3.4dBic at XZ and YZ-plane, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.1
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• pp.142-149
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• 1999

In this paper, Aperture-coupled microstrip array antenna was designed and manufactured for satellite communication at Ka-Band. We analyzed a microstrip radiation element and designed power divider using $\lambda$g/4 transformer and T-junction power divider. A manufactured Aperture-coupled $2\times2$ microstrip array antenna has a resonant frequency of 20 GHz. The experimental results are as followings : resonant frequency of 19.62 GHz, VSWR 1.0692, return loss -29.61 dB, Bandwidth 1.76 GHz and -3 dB beamwidth $42^{\circ}$.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.1
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• pp.105-110
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• 2005

In this paper, a new technique to reduce the phase noise in microwave oscillators is proposed using the resonant characteristics of the Photonic Bandgap(PBG). We applied PBG structure to ground of the microstrip line resonator with the low Q(Quality factor). Therefore, we improved about 10 dBc in contrast to phase noise characteristic of the conventional microstrip line oscillator at 2.4 GHz ＠ 100 MHz offset. Output power is 7.09 dBm.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.435-438
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• 1988

The purpose of this study is to evaluate the discontinuity effects of two kinds of transmission lines. i.e. the strip line and the microstrip line which are popular transmission structures.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.4
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• pp.167-171
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• 2011

In this paper, $2{\times}4$ microstrip patch antenna are proposed to implement K-band satellite communications. The microstrip feed line are inset into the radiation patch to match input impedance. Also the same current in each elements are excited by Kirchhoff's low. The elements distance of proposed array antenna are optimized $0.8{\lambda}_g$ to minimize a mutual coupling and maximize a gain. A power divider network are employed to distribute T-junction divider. As result, the proposed antenna get gain of 14[dBi] at 10.525[GHz].

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.7
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• pp.1022-1032
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• 1999

The radiation characteristics of a microstrip circularly-polarized aperture-patch $8\times8$ array antenna are investigated at X-band. The radiator consists of a truncated square aperture on the ground plane with an inclined rectangular patch inside, and it is coupled by a microstrip line on the opposite side of the ground. The element spacing of the array was chosen as $0.8\lambda_0$so as to minimize the mutual coupling and maximize the gain. A corporate feed network was employed to distribute the power to each element through four Wilkinson and two T-junction dividers. Measurement results for the $8\times8$ array at 10 GHz showed a directivity of 26.3 dBi, a gain of 22.2 dBi, an axial ratio of 2.97 dB, and a side lobe level of -12.7dB. It was observed that when the array size increases, the directivity increases while the efficiency decreases.

• Journal of electromagnetic engineering and science
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• v.12 no.4
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• pp.254-259
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• 2012

This paper presents a closely spaced two-element folded-dipole-driven quasi-Yagi array with low mutual coupling between adjacent elements. The antenna utilizes a T-junction power divider as the feeding network, with an input impedance of $50{\Omega}$. A microstrip-stub is added to the ground plane in the middle of the two elements to improve the mutual coupling characteristics. The folded dipole driver is connected to a $50{\Omega}$ microstrip line via a broadband microstrip-to-coplanar stripline transition with a quarter radial stub. A mutual coupling of less than -22 dB is measured between two folded-dipole-driven quasi-Yagi antennas with a center-to-center spacing of 30 mm ($0.55{\lambda}_0$ at 5.5 GHz). The proposed quasi-Yagi array yields a measured bandwidth of 4.75~6.43 GHz for the -10 dB reflection coefficient and a gain of 6.14~7.12 dBi within the bandwidth range.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.5
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• pp.416-423
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• 2016

In this paper, a conformal type $1{\times}4$ microstrip patch array antenna with tilted antenna beam is presented for UWB sensor applications. Each antenna element comprises E-shaped patch with L-probe feeding to increase the bandwidth. The tilted antenna beam of 20 degree can be achieved with 42 ps microstrip delay lines at the series feeding network with T-junctions. The measured reflection coefficient is >9 dB at 3.5~4.5 GHz. The measured antenna gain and HPBW are >10 dBi and <30 degree at 3.75~4.25 GHz.