• Journal of electromagnetic engineering and science
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• v.17 no.1
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• pp.9-13
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• 2017

In this work, a broadband composite right/left-handed (CRLH) half-mode substrate integrated waveguide (HMSIW) quadrature Wilkinson power divider is proposed. The proposed CRLH-HMSIW quadrature power divider includes a microstrip Wilkinson power divider on the transition structure between the microstrip and HMSIW, and two thru transmission lines for the HMSIW and the CRLH-HMSIW. The measured amplitude, phase difference and isolation between the two output ports of the proposed structure have 1 dB, ${\pm}5^{\circ}$ and less than -15 dB in a wide frequency range of 4.1-6.68 GHz with 47.9% bandwidth, respectively.

• International journal of advanced smart convergence
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• v.11 no.4
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• pp.41-46
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• 2022

This study is a Ku-band array antenna for the manufacture of low-orbit satellite communication terminals, designed to have miniaturization, high gain, and wide beam width. The transmission of low-orbit satellite communication has a right-rotating circularly polarized wave, and the reception has a left-rotating circularly polarized wave. The 4×8 array antenna was separated for transmission and reception, and it was combined with the RF circuit part of the transmitter and receiver, and was terminated in the form of a waveguide for RF signal impedance matching in the form of a transition from the microstrip line to the waveguide. The 30° beam width of the receiver maximum gain of 19 dBi and the 29° beam width of the transmitter maximum gain of 18 dBi are shown. Through this antenna configuration, the system was configured to suit the low-orbit satellite transmission/reception characteristics.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.10 s.89
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• pp.1005-1010
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• 2004

An analysis method of slot-coupled microstripline to waveguide transition is presented to developed a simple but accurate equivalent circuit model. The equivalent circuit consists of an ideal transformer, microstrip open stub, and admittance elements looking into a waveguide and a half space of feed side from a slot center. The related circuit element values are calculated by applying the reciprocity theorem, the Fourier transform and series representation, the complex power concept, and the spectral-domain immittance approach. The computed scattering parameters are compared with the measured, and good agreement validates the simplicity and accuracy of the proposed equivalent circuit model.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.5C
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• pp.506-511
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• 2002

In this paper, waveguide-based power combiner using conventional slotline-to-microstrip transition was proposed at Ka-band. The proposed 2-way and 4-way power combiner consist of waveguide-to-slotline transition, two or four slotline-to-microstrip transitions, and impedance matching networks. Their structures were simulated and optimized by 3-D FEM simulation. The 2-way power combiner showed a very low back-to-back insertion loss of 1.0 dB and return loss better than 15 dB from 25.7 GHz to 29.8 GHz except the resonant frequency. The 2-way power combining approach was extended to 4-way power combining using slotline tee junction. The 4-way power combiner showed the similar performance to that of 2-way power combiner with 2 GHz smaller bandwidth.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.12
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• pp.1435-1444
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• 2008

In this paper, we designed a reduced height waveguide(WG) to microstrip mode converter with a short transition length. The mode converter is composed of a mode converter using E-plane probe and a modified impedance transformer. The mode converter was designed using a probe shorted to top of a 50 ohm ridge WG. The modified impedance transformer was designed to connect the mode converter to the reduced height WG. For wide bandwidth operation, the coupling of the two parts was tuned. The structure of the mode converter was optimized for low loss and wide bandwidth, and the optimized mode converter was fabricated. The performance of the mode converter was extracted using the thru and line S-parameters for back-to-back connections, and the connector loss was calibrated. The mode converter has a right angle structure and short transition length, 7.2 mm. The mode converter shows excellent performances; the insertion loss of 0.12 dB at 15 GHz, and the return loss above 10 dB for the full Ku-band.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.187-192
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• 2017

We investigated the effects of the CSRR-metamaterial on microstrip comb-line array antennas. Microstrip comb-line array antennas was designed with 12 radiators, gain of 16.09dBi and bandwidth of 0.24GHz in the 24GHz ISM band. The designed antenna had radiation beam perpendicular to the antenna plane, co-polarization gain of 16.09dBi and cross-polarization gain of -10.86dBi. the CSRR-metamaterial increased largely the impedance bandwidth of the antenna from 0.24GHz to 3.6GHz. however as co-polarization gain became 10.08dBi and cross-polarization gain became 14.1dBi, co-polarization was mixed with cross-polarization. And the antenna gain lowered by 1.99dB. On the investigation of the dependence on the split-direction of the CSRR rings, it showed nearly the same characteristics for up-splitted ring used case and down-splitted ring used case. However in the case of arranging up-splitted ring and down-splitted ring in alternation, co-polarization gain decreased to -1.29dBi and cross-polarization gain increased to 13.9dBi, which meant the wave was transited to cross-polarization majority wave.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.5
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• pp.965-970
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• 2018

In this paper, the transition of the folded substrate integrated waveguide (FSIW) using two substrates is suggested and applied to the bandpass filter. The FSIW has similar characteristics with the SIW and can be reduced the width of the SIW. The transition between the FSIW to the microstrip is designed by using shorted quarter wavelength line. Also, the bandpass filter is designed by using the FSIW and the elliptic lowpass filter of 5 section. Fabricated bandpass filter has the center frequency of 5.75 GHz and the bandwidth of 33.2%. Also, the insertion loss and return loss at the center frequency are 0.63dB and 19.1dB, respectively.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2005.11a
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• pp.297-302
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• 2005

Right hand circularly polarized Ka band microstrip patch array antenna was designed, manufacture and measurement were carried out. In order to lower axial ratio performance sequential rotation array technique was used. With mono-pulse feed There are sum and delta channel. Waveguide to microstrip transition was used. The 512 array antenna was performed which axial ratio is about 1.ldB in the half power beam width and also 1.ldB at the normal direction. Directivity gain of designed antenna is 32dB.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.2
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• pp.27-32
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• 2018

In this paper, W-band transceiver module for compact radar has been designed and fabricated. Utilizing proposed microstrip-to-waveguide transition, the error between design and implementation is reduced. The proposed transition provides less than 1 dB insertion loss per transition and reliability for fabrication. In order to apply compact radar with dual-polarized monopulse directly, W-band transmitter with 28 dBm output power is designed and developed. Also, 6 channels of receiver module with low noise figure 13.5 dB and maximum 17 dBm input P1dB is developed. Proposed W-band transceiver module is expected compact radar application for dual-polarized monopulse signal processing system.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.5 s.96
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• pp.488-493
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• 2005

In this study, waveguide-to-CPW transitions were developed for integrating waveguide and MMIC at V-band. The finite element method for numerical analysis and repeated experiments were performed to propose two types of waveguide-to-CPW transition. Using quartz substrate, proposed structures were designed for low loss as well as broadband characteristics. These waveguide-to-CPW transitions showed a good reliability and insensitivity to matching precision, and they could be fabricated with lower cost than that of the conventional connectors. Proposed two types of the structure showed insertion loss less than 1.9 dB and return loss better than 14 dB from 53 GHz to 60 GHz except unwanted resonance region, respectively.