• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.181-184
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• 2001

A coplanar waveguide(CPW) on a dielectric substrate consists of a center strip conductor with semi-infinite ground planes on either side. This type of waveguide offers several advantages over microstrip line. It facilitates easy shunt as well as series mounting of active and passive devices. It eliminates the need for wraparound and via holes, and it has a low radiation loss. These, as well as several other advantages, make CPW ideally suited for microwave integrated circuit applications. However, very little information is available in the literature on models for CPW discontinuities. This lack of sufficient discontinuity models for CPW has limited the application of CPW in microwave circuit design. We presented for the characteristics of coplanar waveguide open end capacitance and series gap capacitance. Measurements by utilizing the resonance method were made and the experimental data confirmed the validity of theories. The relationships between the CPW capacitances and the physical dimensions were studied.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.5
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• pp.755-762
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• 2000

In this work, we present the resonant frequencies, Qrad, and impedance bandwidth of rectangular dielectric resonator antenna(DRA)for a broad range of aspect ratios using Dielectric Waveguide Model. These presented data are compared with simulation and measurement. The DRA having relative permittivities of 37.84 and 90 have been fed by a coaxial cable and fed using a aperture-coupled method for comparisions. The approximate resonant frequencies are shown to have the prediction error of about 8% and impedance bandwidth is found to have large prediction variation according to feeding method. The data presented in this paper can be used when the aspect ratios of DRA have to be determined for a given resonant frequency and impedance bandwidth.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.306-310
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• 2002

본 논문에서는 기존의 혼 안테나에 Dielectric rod를 삽입하는 구조를 사용하였다. 입력구조는 Rectangular Waveguide Feed에 Cone을 접목시키는 형태로 구현되었으며 기존의 E-Plane taper구조보다 특성이 양호하며 소형화를 구현해냈다. 제작된 안테나의 중심주파수는 37GHz이며 정재파비 특성 또한 양호하다. 여러 Feeding 구조 중 Bandwidth를 좀더 확장할 수 있는 구조에 초점을 맞추어 대역폭은 13%이상을 구현했으며 시뮬레이션 툴은 Ansoft HFSS V7.0으로 최적화한 후 제작 및 측정하였다. 또한 사용된 Dielectric rod의 제질은 Teflon(ETFE, $\varepsilon$$_{r}$=2.03)을 사용하였다.

• Journal of the Korean Institute of Telematics and Electronics
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• v.24 no.4
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• pp.553-558
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• 1987

A design method of dielectric image-guide grating structures which are applicable for the millimeter-wave system is presented. A dielectric image-guide grating with notches in the sides and also another grating with notches in the top have been designed, fabricated and tested with TM-and TE-mode excitations. From the esperimental results the relatin between TM-TE mode symmetry in the grating structure has been investigated.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.196-196
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• 2012

Graphene, two-dimensional one-atom-thick planar sheet of carbon atoms densely packed in a honeycomb crystal lattice, has grabbled appreciable attention due to its extraordinary mechanical, thermal, electrical, and optical properties. Based on the graphene's high carrier mobility, high frequency graphene field effect transistors have been developed. Graphene is useful for photonic components as well as for the applications in electronic devices. Graphene's unique optical properties allowed us to develop ultra wide-bandwidth optical modulator, photo-detector, and broadband polarizer. Graphene can support SPP-like surface wave because it is considered as a two-dimensional metal-like systems. The SPPs are associated with the coupling between collective oscillation of free electrons in the metal and electromagnetic waves. The charged free carriers in the graphene contribute to support the surface waves at the graphene-dielectric interface by coupling to the electromagnetic wave. In addition, graphene can control the surface waves because its charge carrier density is tunable by means of a chemical doping method, varying the Fermi level by applying gate bias voltage, and/or applying magnetic field. As an extended application of graphene in photonics, we investigated the characteristics of the graphene-based plasmonic waveguide for optical signal transmission. The graphene strips embedded in a dielectric are served as a high-frequency optical signal guiding medium. The TM polarization wave is transmitted 6 mm-long graphene waveguide with the averaged extinction ratio of 19 dB at the telecom wavelength of $1.31{\mu}m$. 2.5 Gbps data transmission was successfully accomplished with the graphene waveguide. Based on these experimental results, we concluded that the graphene-based plasmonic waveguide can be exploited further for development of next-generation integrated photonic circuits on a chip.

• Journal of electromagnetic engineering and science
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• v.5 no.3
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• pp.140-145
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• 2005

In this paper, an experimental investigation for return loss and a software-based prediction for interference level of single-packaged filtering antenna composed of dielectric waveguide filter and PCB(Printed Circuit Board) slot antenna in transceiver module have been carried out with several different feeding structures in millimeter-wave regime. The implementation and embedding method of the existing air-filled waveguide filters working at millimeter-wave frequency on general PCB substrate have been described. In a view of the implementation of each components, the dielectric waveguide embedded in PCB and LTCC(Low Temparature Co-fired Ceramic) substrates has employed the via fences as a replacement with side walls and common ground plane to prevent energy leakage. The characteristics of several prototypes of filtering antenna embedded in PCB substrate are considered by comparing the wideband and transmission characteristics as a function of bent angle of transmission line connecting two components. In addition, as an essential to the packaging of transceiver module working at millimeter-wave, miniaturization technology maintaining the performances of independent components and the important problems caused by integrating and connecting the different components in different layers are described in this paper.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.11
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• pp.88-96
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• 1996

Periodically slotted dielectricalloy filled parallel-plate waveguide as a leaky wave antenna is designed and fabricated at the center frequency of 10.0GHz. The antenna was fed by use of a hog-horn structure. The hog-horn and the two side walls and the lower plate of parallel-plate waveguide were fabricated form duralumin. The upper plate of parallel-plate waveguide with 48 periodic slots was made of copper plate of 1mm thickness. The dielectric material inside the parallel-plate waveguide was chosen to be paraffin. The experimental radiation pattern for the fbricated antenna was compared with the theoretical results for the finite periodic structure.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.10 no.5
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• pp.266-272
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• 1985

The analysis of a cylindrical waveguide which is partially filled with dilectric materials has been performed for many years. Hut most of the analyses were an approximation by the analytic method. In this paper a FORTRAN program for numerical analysis is introduced to calculate the propagation constant for TE. TM and Hybrid modes. The results of the numerical calculation can be used to determine the resonant frequencies for TM. TE and Hybrid modes in the dielectric resonator.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.156-157
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• 2000

The amplification method using evanescent wave coupling has a long history and has been widely used as a new lasing method, especially, in the waveguide optics$^{(1)}$ . In particular, it has been observed experimentally that when the light wave propagating in a dielectric medium is totally reflected at the planar interface between the dielectric and a pumped active medium, the reflectance may be greater than unity, i.e., amplification is possible$^{(2)}$ . There were several attempts by other authors to explain this enhanced internal reflection (EIR) classically$^{(3)}$ . They commonly introduced a complex refractive index for the active medium with its imaginary part being negative, and this scheme was also used to describe an amplification process in a waveguide having active-cladding region$^{(4)}$ . However these theories are phenomenological, using macroscopic constants, and therefore a microscopic theory is needed to understand EIR in a fundamental level. (omitted)

• Progress in Superconductivity and Cryogenics
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• v.4 no.2
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• pp.11-15
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• 2002

High speed probe for measurement of sin91e flux quantum circuits is comprised of coaxial cables and microstrip lines in order to carry high speed signals without loss. For the impedance matching between coaxial cable and microstrip line, we have determined the dimension of the microstrip line with 50${\Omega}$ impedance by simulation and then have investigated the effect of line width and cross-sectional shape of signal line, dielectric material, thickness of soldering lead at the coaxial-to-microstrip transition Point, and the an91c between dielectric material and end part of the signal line on the characteristics of signal transmission of the microstrip line. From the simulation, we have found that these all parameter's had influenced on the characteristic of signal transmission on the microstrip line and should be reflected in fabricating high speed probe, We have also determined the dimension of coplanar waveguide to fabricate testing sample for performance test of high speed probe.