• The Journal of the Acoustical Society of Korea
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• v.13 no.1E
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• pp.5-10
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• 1994

It is obtained the general expessions of the numerical method are applied for the TEM-mode analysis of multu-layer multi-coupled microstrip lines, In this paper, coupled microstrip are replaced by three-coupled microstrip lines in special aplications. Three-layer versions of three-coupled microstrip lines are specially attactive because of the additional flexibilities offered by three-layer configuration. This structure can be used for obtaining large capacitance and preventing coupling among microstrip lines in filter and coupler. Sappihre is chosen for anisotropic substrates material. The permittivity parallel to the optical axis is higher than the permittivity in the plane perpendicular to this axis.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.4
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• pp.532-541
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• 2001

In the case of the microstrip antenna with the coaxial probe-feeding, there is rapidly-varying patch current near the point where the probe feed is connected to the patch. We represent this current distribution using the attachment mode that insures continuity of currents from the feed to the patch. In this paper, we can accurately analyze the effect of a cover layer or radome for an antenna with the attachment which model rigorous probe feed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.10
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• pp.925-933
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• 1991

Caracteristics of cylindrical rectanyular patch microshtrip resonator are analyzed by cavity model. To minimize the error of resonant frequency due to fringing field, the resonant frequency is calcylated by the concept of effective dielectric constant. The transmisson type resonator operating at 3GHz is designed and manufactured. The measured data of the resonant frequency and reflection loss are 3.019Ghz and \ulcorner32.78dB respectively. These results nearly coincide with theoretical results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.1
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• pp.26-35
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• 1996

In this paper, characteristics of the electromagnetically coupled broadband microstrip antennas are analyzed by the Finite Difference Time Domain (FDTD) method, and antenna para- meters are optimized to get maximum bnadwidth. By using short radial tuning stub in microstrip feedline, electromagnetically coupled microstrip antenna shows broadband ($\simeq$13%) characteristics, and the characteristics are varied as a function of radius, radial angle, and position of the radial tuning stub. Operating frequency, return loss, VSWR and input impedance are calculated by Fourier transforming the time domain results. After optimization of the parameters, maximum bandwidth of the radial stub tuning microstrip antenna is about 15% and the ripple char- acteristic of the VSWR is better than the rectangular tuning stub microstrip antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.7 no.5
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• pp.384-394
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• 1996

The propagation properties of square and Gaussian pulse signals on the microstrip line are investigated by using proper conventional models to meet the frequency range of a pulse, accuracy, and geometrical requirements of the microstrip line. Numerical integration technique which has its accuracy and is easily simulated, is used to obtain the time domain response of pulse signals. The dispersion of pulse signals is analyzed regarding to the relative permittivity $\varepsilon_r$, substrate height h, strip width w of the microstrip line and pulse width $\tau$ of signal pulse. The simulation results show that small relative permittivity and small rationale of w/h are advantageous for the dispersion of the pulse signals, and that pulse signals with small bandwidth cause smaller dispersion. The results of this paper are compatible to the trade-off determination of relative permittivity, substrate height, strip width and pulse width of signal pulse when a design of MIC and MMIC is necessary.

• Journal of the Korean Institute of Telematics and Electronics
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• v.19 no.3
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• pp.13-18
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• 1982

This Paper is an experimental study on the effective dielectric constant of microstrip line. To quantify the dispersive effects on a microstrip line, the effective dielectric constant, which is the ratio of free space wavelength to guide wavelength, is calculated for teflon substrates. The calculation is based on the Fourier transform of the current distribution on microstrip line. Measurements of effective dielectric constant using a microstrip elliptic resonator and ring resonator are also described. As a result, the computed values of effective dielectric constant agree almost all with measured values, using ring and elliptic resonator, in case of w/h or the ratio of microstrip width to substrate thickness equal unity over frequency range of 8 to 12GHz.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.12
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• pp.22-27
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• 2007

In this paper, a novel voltage-controlled oscillator (VCO) using the microstrip square open loop split ring resonator (OLSRR) is presented for reducing the phase noise. For this purpose, the square-shaped split ring resonator (SRR) haying the form of the microstrip square open loop is investigated. Compared with the microstrip square open loop resonator, the microstrip square OLSRR has the larger coupling coefficient value, which makes a higher Q value, and has reduced the phase noise of VCO. The VCO with 1.7V power supply has the phase noise of $-120\sim-116.5$ dBc/Hz @ 100 kHz in the tuning range, $5.746\sim5.854$ GHz. The figure of merit (FOM) of this VCO is $-200.33\sim-197$ dBc/Hz @ 100 kHz in the same tuning range.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.11
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• pp.1767-1773
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• 1993

In this paper, the coupling characteristics as well as the self and the mutual Impedance of a two-element probe-fed stacked circular microstrip array antennas are presented. A full wave analysis for the structure is performed In the spectral domain using the vector Hankel transform(VHT). Also, we presented measured results for the impedance, the coupling characteristics of the antenna and the variation of the coupling with the distance between the two elements. Finally, the calculated and measured results are shown to agree well wlth each other through comparisons.

• Journal of the Korean Institute of Telematics and Electronics
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• v.13 no.1
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• pp.31-34
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• 1976

In this paper, the characteristics, especially impedance matching behavior of linearly tapered transmission line which impedance is varied linearly is analyzed. Also impedance matching of nonuniform microstrip which characteristic impedance or width of strip is varied linearly are experimentally investigated.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.4
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• pp.519-526
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• 2002

In this paper, a microstrip patch array antenna for a Doppler radar at 10.525GHz is desinged and fabricated. To be used for mobile radar system, the antenna is fabricated on a single layer laminate to resist a fire impact and is covered with the Teflon foam. To obtain the desired characteristics, the array antenna is designed 4$\times$8 array using a corporate 3-dB amplitude taper. Also, using square patch elements, the antenna can be converted to a circular polarized antenna later. The designed and fabricated array antenna has the reflection coefficient$({S_11})$ -53.498dB, the horizontal beam width of $10^{\circ}$, the vertical beam width of $18.8^{\circ}$, the gain of 21dBi, the bandwidth of 220MHz for VSWR<1.5 and a side lobe level of less than -17.5dB.