• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.412-416
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• 2005

In this paper we propose low-impedance and miniaturized a wilkinson power divider on MMIC passive component which was fabricated by a novel microstrip line structure employing periodically perforated ground metal (PPGM). The novel microstrip line structure showed much lower impedance and shorter guided-wavelength than conventional one. Using the novel microstrip line with periodically perforated ground metal, a miniaturized 17 ${\Omega}$ power divider was fabricated. The line width of the power divider was 20 ${\mu}m$, and the size of it was 0.110 $mm^2$, which is 21 % of conventional one. The power divider exhibited good RF performances from 10 to 20 GHz.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.8B
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• pp.1035-1040
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• 2001

SNU-ISRC 0.25$\mu\textrm{m}$ pHEMT 표준 공정을 사용하여 Ka-band에서 동작하는 0.2W급 MMIC CPW 전력증폭기를 설계, 제작하였다. 기존의 MMIC 공정에서 사용되는 마이크로스트립 전송선 대신 CPW 전송선을 사용함으로써 보다 간단하고 저가의 공정이 가능하였다. 전력증폭기의 설계에서는 보다 넓은 주파수 대역에서 원하는 출력전력을 얻기 위해서 출력단을 Wilkinson coupler를 사용하였는데, 일반적으로 Wilkinson coupler에 사용되는 50Ω 특성임피던스 전송선 대신에 25Ω 특성임피던스 전송선을 사용하여 좋은 출력단 전력 정합과 출력 반사손실을 동시에 얻을 수 있었다. 제작된 전력증폭기의 측정결과, 주파수 27GHz에서 출력전력 23.4dBm과 Power-added Efficiency 21.7%의 결과를 보였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.4
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• pp.575-581
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• 2000

In this paper, a new active phase shifter is proposed using a vector sum method, and a unique digital phase control method of the circuit is suggested. The proposed scheme was designed and implemented using a Wilkinson power combiner/divider, a branch line 3 dB quadrature hybrid coupler and variable gain amplifiers (VGAs) using gate FETs(DGFETs). Furthermore, it was also shown that the proposed scheme is more efficient and works properly with the digital phase control method.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.6
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• pp.363-644
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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 interening 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.

• Transactions of the Korean hydrogen and new energy society
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• v.16 no.4
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• pp.324-333
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• 2005

The kinetics of external hydrogen embrittlememt is considered. The equation of the crack growth rate (CGR) is derived from modification of the model developed by Wilkinson and Vitek. After calculation of hydrogen pressure build-up in the void, the effect of the internal hydrogen pressure on the void growth is added. The CGR is expressed by two terms. One is the term dependent on the critical stress, which is exactly same as Wilkinson and Vitek. The other is term dependent on the pressure of the hydrogen in void.

• Communications of Mathematical Education
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• v.22 no.4
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• pp.445-457
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• 2008

Although both theory and experiment are very important parts in sciences, especially in mathematics, theory only seems to be very important. But the subject of numerical analysis needs both theory and practice in computer. In this paper, I provide some Matlab program codes and matrices which are used in good understanding OR methods in class.

• Journal of Digital Convergence
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• v.12 no.4
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• pp.343-348
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• 2014

This paper suggested a theoretical approach and an implementation for the design of an unequal Wilkinson power divider with a high dividing ratio operating at two-frequencies. The T-section transmission lines and the two-section of Monzon's theory are proposed to operate a dual-band application. To achieve the high dividing ratio divider, the high impedance line using a T-shaped structure and low impedance lines with periodic shunt open stubs are implemented. For the validation of this divider, a dual-band power divider with a high dividing ratio of 5 is simulated and measured at 1 GHz and 2 GHz. The measured performances of the divider are in good agreements with simulation results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.8 s.99
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• pp.835-841
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• 2005

In this paper, a novel sized-reduced CPW(Coplanar Waveguide) balun is proposed. It has a crossing structure between signal line and ground planes of CPW transmission line for the $180^{\circ}$ phase inversion. The$3{\lambda}/4$ CPW transmission line is reduced to ${\lambda}/4$ in physical length while the electrical length is preserved to $270^{\circ}$ by the $180^{\circ}$ phase inverting structure, while the previous balun by Lim et at. has a long $3{\lambda}/4$ transmission section to from the Wilkinson divider structure having out of phase between output ports. In addition, the measured data which show the crossing structure has the wanted $180^{\circ}$ phase change is presented in this work.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.5
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• pp.383-388
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• 2018

This paper presents a 1.8 GHz six-port-based impedance modulator using CMOS technology, which can select an arbitrary load impedance with switch control. The proposed 1.8-GHz impedance modulator comprises a Wilkinson power divider, three quadrature hybrid couplers, and four SP3T switches for each load impedance selection. The measured insertion loss of -13 dB and the input/output return losses of >10 dB are achieved in the range of 1.4~2.2 GHz. The low drop output regulator for a stable 3.3 V DC power and the serial peripheral interface(SPI) for an easy digital control are integrated. The chip size, including the pads, is $1.7{\times}1.8mm^2$.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.8
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• pp.24-32
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• 2000

In this paper, we have designed and fabricated a new type power divider to be efficient to a size and electrical performance by folding each quarter-wavelength 70.7 Ω section into a tightly-coupled "meander-line" and inserting a slit. In this type, because of coupling, the electrical phase of quarter -wavelength line and the performance change. For this reason, with the inductive slit and the tuning of quarter-wavelength line length, we have compensated for those. The inductance value of the inserted slit is decided by its width and depth, therefore, we could improve the electrical performance through optimization of inductance. Input and output return losses of the designed power divider were -34.2 dB, -34.3 dB respectively, and isolation was -36.7 dB at 1.75 GHz. Besides, a new design approach reduced occupied substrate area by 3:1 approximately.