• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.430-432
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• 1988

Radiation admittance of the rectangular microstrip antenna is calculated by using equivalent ${\pi}$-network parameters of the slit in the wall of the parallel plate waveguide filled with homogeneous dielectric. Using equivalent transmission line model, return loss is calculated and compared with experimental result. Calculated values for the return loss show good agreement with experimental values.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.2
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• pp.135-140
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• 2009

This paper discusses how to change the electromagnetic waves' property in the cut-off causing discontinuity existing in the guiding structure of the RF passive component by using the metamaterial and elaborates on its principle. Particularly, we find and explain, from the viewpoint of electromagnetics and circuit theories, the so-called tunneling condition that when the segment with an extremely narrow cross-section leading to blockage in the parallel-plate waveguide is given the ENZ(Epsilon Near Zero) for its filling material, the wave starts to propagate through the segment. The analysis method as a transmission-line theory taking the discontinuity and material change into consideration is shown valid through the comparison with other methods for analyzing parallel-plate waveguides, and provides the illustration of the S-parameters and impedance describing the characteristics of the tunneling.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.637-640
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• 2006

In this paper, a microstrip antenna with a small loop consisting of the left and right parallel plate to load capacitor is proposed. It is obtained the improved small size than the antenna of the transformed Uh and the antenna of the left and right parallel plate to load capacitor on QMSA. Equivalent circuit of transmission line model is designed to find more accurate resonant frequency. Also, the designed and fabricated antenna can receive both vertically and horizontally polarized waves to operating frequency of 1.5GHz. Therefore proposed antenna is available as a small antenna for wireless communication and will be quite useful for indoor communication

• Korean Journal of Optics and Photonics
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• v.7 no.1
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• pp.28-36
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• 1996

We have constructed and studied a laser system which consists of a multiplex spark gap with 8 couples of spark gaps and a multiple parallel plate capacitor type Blumlein transmission line circuit. In this laser system, the length of the laser tube, the length of the multiplex spark gap and the total thickness of the transmission line circuit are chosen to be 520 mm. The experimental results show that one couple of spark gaps cannot give a uniform and complete lasing through the whole laser tube. All the more, a multiplex spark gap could not perform completely and synchronously. However, a multiplex spark gap in found to contribute to the increase of laser output power and the laser has performed the best when the location is three quarters of the laser tube length.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.6
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• pp.1111-1116
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• 2007

Antennas of the near field detection radar require little distortion in time domain caused by multi reflections between feed and open ends of the antenna, so that help to discriminate the target signal from the clutters. The resistive loading techniques have been used to reduce the late time distortions in order to prevent masking of target. In this paper, we design a microstrip antenna with two arms having sloted lines, which have inductance loading effect. Implemented antenna shows better performance on reducing late-time ringing, and the peak value of the received signal becomes 45% greater than the one by the antenna with two non-sloted lines.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.2
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• pp.364-372
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• 1994

Theoretical method for analyzing the radiation pattern of cross-type 5-patch rectangular microstrip antenna is presented. The equivalent circuit of the array antenna is represented by the conventional transmission line model and the radiation admittance derived from the equivalent circuit of the slitted parallel-plate waveguide filled with a dielectric. The calculated results for the radiation pattern are compared with the measured values.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.2
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• pp.35-40
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• 1989

In this paper, a new method which simultaneously gives the radiation conductance and susceptance of the rectangular microstrip patch antenna. This solution is derived from the load admittance of the equivalent ${\pi}-$network circuit of the slitted parallel-plate waveguide filled with homogeneous dielectric. Our theoretical results for the radiation admittance are compared with other theoretical results. Also, our theoretical return loss and resonant frequency which are calculated by use of the equivalent transmission line model are in fairly good agreement with the experimental results.

• Korean Journal of Optics and Photonics
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• v.1 no.2
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• pp.169-177
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• 1990

We have constructed the laser system which was consisted of a high voltage pulse poner supply, a rapid high voltage spark gap and the Blumlein transmission line circuit of the multiple parallel plate capacitor type, and have studied the self-preionization effect from this laser system without additional modifications. The value of inductive or resistive loading of the laser oscillator seems to have a significant effect on the preionization. The optimal operational condition of this laser system was obtained at the inductive loading of L = I mtl across the laser tube with the spark gap distance of 6.0 mm. nitrogen pressure of 50 torr, when repetition rate was 70 Hz. Stability was found to be better than 2.0Yo and EIP was 867 V/cm.torr.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.5
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• pp.87-93
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• 2011

A threat of the EMP(Electromagnetic Pulse) is recently increasing, so the development of electromagnetic security technology against the EMP is needed. However, the state of the domestic electromagnetic security technology against the EMP is lower level than the foreign. In this paper, the bounded-wave EMP simulator antenna for the development of electromagnetic security technology against a threat of the EMP is designed. The structure of the designed antenna is from a sort of the basic form of the bounded-wave EMP simulator such as a parallel-plate simulator for testing EMP immunity performance within the EUT(Equipment Under Test). The design processes of the designed simulator is including wave launcher, transmission line and termination taper. In the working volume of the designed antenna, the test object within 30 cm is forming predominant TEM field, so it is confirmed that the designed EMP simulator antenna can be used as the EMP simulator.

• Journal of the Korea Convergence Society
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• v.9 no.11
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• pp.29-35
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• 2018

In this paper, we proposed a high sensitivity sensor that can detect the concentration change of Nacl aqueous solutions by using a slot coupling capacitor resonator in sub-microwave band. The resonator applied to the sensor consists of a parallel plate capacitor connected to an inductive slot utilizing the ground plane of the microstrip line. Based on the measurement data of the dielectric characteristics according to the concentration change, the resonance frequency was determined in the UHF band where the concentration change is evident and the Nacl aqueous solution is inserted into the capacitor. Based on the simulation, the proposed resonator was designed and fabricated. The concentration level was varied from 0 to 400 mg/dl as 100 mg/dl step, and the transmission scattering coefficient ($S_{21}$) was successfully measured. Experimental results show that it is applicable to the concentration detection sensor in Nacl aqueous solution by obtaining minimum 1.8 dB($S_{21}$) at each step.