• Journal of the Korean Institute of Telematics and Electronics
• /
• v.14 no.5
• /
• pp.7-14
• /
• 1977

Conventionally, a TIVT has been used for high power amplification in the microwave frequency range. However, an ultra-high-power amplifier in the 2GHz range has successfully been designed and fabricated employing high power transistors developed recently and available commercially. In the design of the amplifier, a balanced-pair configuration is adopted in order to obtain very high microwave power, and a good impedance matching is achieved by making use of microstripline techniques. For the RF power divider as well as combiner, an approach of stripline directional coupler isadopted because of its easiness in fabrication. The coupler so designed and fabricated indicates a satisfactory performance as a quadrature hybrie coupler. Measurements on the amplifier developed for an immediate commercial application also exhibit excellent overall performance characteristics RF power output, 14 watts, gain 14dB, frequency bandwidth, 160MHz, effciency 40%.

• Journal of Broadcast Engineering
• /
• v.23 no.6
• /
• pp.925-930
• /
• 2018

In this paper, we present a low profile dual-microstripline-fed double 4-arrayed meander monopole antenna with a cross-type element back by separated four-segments mesh-type reflector. The cross-type element and separated four-segments mesh-type reflector leads to enhance radiation patterns and antenna gain characteristics. The measurement value of the proposed antenna show that it has dipole-like radiation pattern characteristics. The experimental peak gain of fabricated antenna is about 2.89 dBi, which presents relatively high gain characteristics for a low profile(small-size) one. This antenna can be applied mobile RFID(radio frequency identification) readers, small medical instruments, broadcasting and home-networking operations, and other low profile high-gain systems.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.16 no.3
• /
• pp.49-56
• /
• 1979

A new microwave frequency disriminator in MIC is described which was developed using realization theory appropriate to a transmission line frequency discriminator designed to be used in the VHF range. It is experimentally verified that the discriminator is linear in a 600 MHz bandwith and has VSWR less than 1.2 in that range in agreement with the theoretical model.

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.147-150
• /
• 1999

A T-shaped microstripline-fed printed slot array antenna having wide bandwidth, high gain, and narrow bandwidth is presented in this paper. The proposed antenna is analyzed by using the transmission line model method. We fabricated 4$\times$1 microstrip slot array antenna and measured its return loss and radiation pattern. The maximum bandwidth of this array antenna is from 1.43 ㎓ to 2.60 ㎓, which is 58.1% for the VSWR $\leq$ 2.

• Proceedings of the KIEE Conference
• /
• 1996.07c
• /
• pp.1485-1488
• /
• 1996

This paper presents a method for analyzing electromagnetic field of planar microwave structures, which is based on Finite Element Method and optimizes structure of microstripline on Printed Circuit Board.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.1
• /
• pp.8-15
• /
• 1998

An analysis of the microstripline is started as an assumption of the axial & transveral current distribution. Applying the boundary conditions to the scalar wave equations of a electric & magnetic potential, the two simultaneous coupled integral equations are produced. The electronmagnetic fields in microstrip line can be obtained by solving these two coupled integral equaltion. In general, either a numerical analysis method or a Galerkin method was used to solve them. In this paper, a residue theorem is proposed to solve them. The electromagnetic fields are expressed as integral equations for LSE and LSM mode in the spectral domain. Applying a residue theorem to the Fourier transformed equation and Fourier inverse transformed equation which is necessary for interchanging the space domain and the spectral domain, the electromagnetic fields are expressed as algebraic equations whichare relatively easier to handle. the distributions of the electromagnetic field are shown at the range of -5w/2.leq.x.leq.5w/2, 0.lep.y.leq.4h for z=0. It agrees well with the results of the Quasi-TEM mode analysis.

• Proceedings of the KIEE Conference
• /
• 1997.11a
• /
• pp.308-310
• /
• 1997

In this paper, to anlayze electromagnetic distribution, measure the variation of relative permittivity of Glass-epoxy substrate for Computer-main-board and Tenon substrate for handphone or PCS in the frequency range $100[MHz]{\sim}1[GHz]$, in room temperature. To measure relative permittivity, suggested the Microstripline method. As the frequency increase, the variation of relative permittivity of Glass-epoxy is bigger than Tefoln's. And simulate the electromagnetic distribution on the PCBs in the infinite region applying the open boundary condition with these results by Finite Element Method.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.1420-1421
• /
• 2008

In this paper, a dual band microstrip filter is designed for RFID Application. Both magnetic and electric coupling structures are implemented to provide high performance passband response. The measured results demonstrate that reflection factor is 20dB and 15dB at 912MHz and 2450MHz. The measured loss is 2.6dB and 2.8dB at 912MHz and 2450MHz, respectively.

• Proceedings of the Korean Society of Marine Engineers Conference
• /
• 2005.06a
• /
• pp.417-422
• /
• 2005

Using the novel microstripline with periodically perforated ground metal, a miniaturized 1/4 ${\lambda}$ transformer was fabricated. The line width of the 1/4 ${\lambda}$ transformer was 20${\mu}m$ and the size of it was 0.0085$mm^2$, which is 1.2% of conventional one. The 1/4 ${\lambda}$ transformer exhibited good RF performances from 10 to 25GHz.

• Journal of electromagnetic engineering and science
• /
• v.11 no.2
• /
• pp.122-127
• /
• 2011

A general analysis of an aperture-coupled vertically mounted strip antenna is presented to examine its circuit characteristics. Based on the present analysis, an equivalent circuit model is developed, and an analytic or semi-analytic evaluation of the related circuit element values is described. The effects of structure parameters on the antenna characteristics were studied with the developed equivalent circuit, and the design curves were obtained. To check the validity of the proposed analysis and design theory, two C-band antennas (5.0 GHz and 4.5 GHz) were designed and fabricated. Their computed characteristics, derived from the proposed network analysis, were compared with the measurement and simulation results. The error of the current model in predicting the operating center frequency was less than 0.50 %. In addition, the observed bandwidth was found to be comparable to the conventional microstrip antennas. All the results fully validated the efficiency and accuracy of the proposed analysis and network model.