• Journal of Advanced Navigation Technology
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• v.19 no.3
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• pp.224-229
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• 2015

In this paper, we derived the design equation and implemented the unequal Gysel power divider that is one external resistors using the ABCD parameters analysis. Conventional unequal Gysel divider is difficult to obtain the characteristics of isolation and return loss at between output ports because it can't select a theoretical value of external resistor. To solve those problems, we design the new unequal Gysel power divider with transmission lines and one external resistor that has the characteristics of conventional unequal Gysel divider. To validate this design method, we simulated and measured an 4: 1 unequal Gysel power divider at the center frequency 1 GHz. The measured performances agreed well with the simulation results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.9
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• pp.1048-1057
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• 2012

In this paper, a new compact dual-band unequal power divider is suggested. Instead of the quarter wavelength transmission line(TX-line)s for the branches of the conventional Wilkinson's power divider, we use composite right- and left-handed(CRLH) phase-shift lines and can reduce the physical length. With the non-linear dispersion of the meta-meterial, each branch in the proposed divider is designed to have $+90^{\circ}$ and $-90^{\circ}$ at $f_1$ and $f_2$ respectively. To validate the proposed method, the performances of the circuit and full-wave simulation results are shown with the CRLH dispersion curve. The measurement results are compared with the simulation results. Also, the size reduction effect by the proposed scheme is addressed.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.182.1-182.1
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• 2012

태양전력 조절기는 태양전지에서 전력을 생성하여 배터리를 충전하고 인공위성의 모든 부하에 전력을 공급하는 역할을 한다. 이러한 태양전력 조절기는 신뢰성 확보와 대전류 처리를 위해 병렬운전한다. 병렬운전 시 전류가 각 태양전력 조절기에 균등하게 분배되지 않을 경우, 한 태양전력 조절기에만 과도한 전류가 흐르게 되고 해당 태양전력 조절기에 문제가 발생한다. 따라서 병렬운전 하는 각 태양전지 조절기에 전류를 균등하게 분배하기 위해 전류 제어기가 필요하다. 전류 제어 방식에는 Inner Loop방식과 Outer Loop 방식이 있다. Inner Loop방식은 전류 제어기가 태양전력 조절기의 전류를 제어하고, 전류 제어기의 기준 전압을 외부의 전압 제어기가 제어하는 방식이다. 한편, Outer Loop 방식은 전압 제어기가 태양전력 조절기의 전압을 제어하고, 전압 제어기의 기준 전압에 태양전력 조절기의 전류 정보를 더하여 전압을 제어하면서 간접적으로 전류를 제어하는 방식이다. 한편, 태양전지는 전압과 전류가 강한 비선형성 관계를 가지므로 태양전지의 동작점에 따라 태양전력 조절기의 소신호 특성이 변화하고, 이는 전류제어기 안정도에 심각한 영향을 미친다. 따라서 본 논문에서는 태양전지의 각 동작점에 관계없이 전류 제어기가 안정적으로 태양전력 조절기의 전류분배를 수행할 수 있도록 Inner Loop방식과 Outer Loop방식의 전류 제어기를 해석하고 두 방식을 비교한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.6
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• pp.715-724
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• 1998

The FDTD(Finite-Difference Time-Domain) method is applied to analyze an unequal Wilkinson power divider. Unequal Wilkinson power divider has complex structures and the standard Yee Cell modeling method is not appropriate. In this paper, nonuniform gridding and subcell modeling are used to accurately analyze the characteristics of an unequal Wilkinson power divider. For comparison, the numerical results are presented with those from a commercial circuit simulator.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.2
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• pp.245-251
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• 2017

The proposed variable pawer divider in this paper is composed of one equal power 2-way Wilkinson power divider, two variable phase shifters with 90-degree phase variation to be connected two output paths of the 2-way power divider, and one branchline coupler to combine output signals of two variable phase shifter. The proposed variable power divider can theoretically have an arbitrary power division ratio ranging from ${\infty}:1$ to ${\infty}:1$ due to 90-degrees phase variation of two phase shifter. The proposed power divider circuit fabricates on laminated TLX-9(h=20 mil, er=2.5; Taconic) with a center frequency of 1.7 GHz. The power division ratio of the fabricated prototype varies from about 1:100 to 200:1, with an input reflection characteristic(S11) of below -16 dB, an insertion loss of about -1.0 dB, and an isolation characteristic of below -17 dB between two output ports in the range 1.65-1.75 GHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.2
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• pp.253-259
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• 2016

This paper introduces a new variable power divider circuit with an arbitrary power division ratio ranging from $1:{\infty}$ to ${\infty}:1$. The proposed power divider circuit consists of one branch-line coupler to be a good input matching characteristic, two variable phase shifters with 90-degree phase variation to be connected two output paths of the branch-line coupler, and one ring-hybrid coupler to combine output signals of two variable phase shifter. The power division ratio between the two output ports of the proposed power divider can be easily controlled by the phase variation of the two phase shifter. The proposed power divider circuit fabricates on laminated RF-35 (h = 20 mil, er=3.5; Taconic) with a center frequency of 2 GHz. The power division ratio of the fabricated prototype varies from about 1:1000 to 5000000:1, with an input reflection characteristic(S11) of below -20 dB, an insertion loss of about -1.0 dB, and an isolation characteristic of below -17 dB between two output ports in the range 1.9-2.1 GHz.

• Journal of Navigation and Port Research
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• v.26 no.3
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• pp.289-294
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• 2002

The broadband high power 3-way combiner was designed and fabricated for the digital TV repeater. To achieve increase of the bandwidth and the high power capability, Wilkinson type power divider was adopted in our research. First of all, Wilkinson type power divider of equal-split and unequal-split were combined, and the characteristics of the four port in-phase power combiner was simulated for each thickness of dielectric substrates. As the results of simulation, the power combiner fabricated by using dielectric substrate of 120 mil-thickness has the characteristics as follows: insertion loss of less than -651 dB, reflection coefficient of less than -13 dB, isolation among the output ports of less than -15 dB, and pose difference among the output ports of smiler than 13$^{\circ}$. Therefore, this power combiner was possible to improve the limit of microstrip line width due to high impedance, the problem of power loss due to interaction between strip lines in a high power combiner and narrow bandwidth simultaneously. Furthermore, making broadband and high power could be achieved since the fabricated 3-way combiner has good characteristics of insertion loss, the reflection coefficient, separation between ports, and phase difference.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.1
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• pp.63-69
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• 2010

In this paper, a new design method of asymmetrical configuration of main amplifier and peaking amplifier using changed bias point is proposed for excellent linearity, instead of the conventional Doherty structure. We have utilized the uneven wilkinson power divider for the unequal power drive at the input network of amplifiers. And we proposed a compensating method of the decreasing efficiency due to improving linearity using 3-stage Doherty structures. From the simulation results of asymmetrical Dohertry power amplifier and asymmetrical 3-stage Doherty power amplifier with uneven power drive are implemented. From the implementation and measurement results of the each amplifier, IMD characteristics have -55 dBc as the good efficiency of 13% compensates the decreased entire efficiency due to the improving linearity characteristics.