• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.7
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• pp.1138-1147
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• 1999

In this paper, two types of $2\times2$ Rx/Tx microstrip patch antenna are proposed to implement Ku-band satellite communications. The single-fed dual resonance patch antenna as the first type derives perpendicular polarizations at two resonant frequencies from a single patch radiator, using aperture coupling via a bended single-feeding line and a cross-shaped slot. The double-fed dual resonance patch antenna as the second type implements dual resonance with mutually orthogonal polarizations by mixing the two feeding mechanisms of the microstrip line and the aperture coupling. Especially, in the double-fed dual resonance antenna case, air-gap is introduced to broaden the bandwidth. Through measurement, each of the two types of antenna was verified to function properly both Rx and Tx. The double-fed dual resonance antenna shows excellent performance in the bandwidth and the crosspolarization characteristics.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.1
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• pp.32-43
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• 1999

In this paper, the transformed QMSA to load a capacitor without limitation of the electric force on QMSA(Quarter-wavelength Microstrip Antenna) is designed. Bandwidth of the designed and manufactured antenna is 5.7% at the resonant frequency of 2.0 GHz and the resonant frequency and bandwidth versus change of any arbitrary feed point is observed. Since the size of wide slot width between the left and right parallel plate to load a capacitor is very wide bandwidth, will be suitable for very wide bandwidth communication. The radiation pattern characteristics of the designed antenna based on the dipole structure and the aperture structure analysis method. As calculation results, relative backward radation is - 5 dB.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.5
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• pp.614-620
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• 1998

In this paper, we analyze theoritically the propagation and radiation characteristics for elliptical corrugated waveguides. The solutions of wave equations in an elliptic cylinder system are obtained in terms of Mathieu functions of 1st and 2nd kind. The electromagnetic fields in the elliptical corrugated waveguide can be represented by series and products of angular and radial Mathieu functions. By using impedence matching at the boundary between the inner region and the slot region, characteristic equations are derived. Then the characteristic equation is solved for $HE_{11}$ mode which is dominant mode in the elliptical corrugated waveguide and the fields in the aperture is calculated. And the propagation pattern for the elliptical corrugated waveguides is calculated through the field equivalence principle.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.1
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• pp.8-15
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• 1998

In this paper, to improve the bandwidth of microstrip antenna, we discussed parasitic patch structure coupled capacitively at radiating slot. To reduce the overal size of antenna,$\lambda$/4 short structure is accepted instead of $\lambda$/2 patch. Since ground plane is reduced, backward radiation is occurred. The characteristics of the designed antenna is evaluated, based on the transmission line model and the aperture analysis method. And by computer program the radiation pattern and return loss are evaluated. As simulation results, backward radiation is -15 dB. Bandwidth of constructed antenna is 167 MHz at the resonant frequency of 2.45 GHz, which is very broad, compared to conventional microstrip antennas. Therefore the proposed antenna will be suitable for very wide bandwidth communications.

• Journal of Advanced Navigation Technology
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• v.7 no.2
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• pp.101-107
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• 2003

In this study, we provide a single element log-periodic antenna that the feeding networks and array structures are aperture coupled and series dipole array type. We made the antenna for direct receiving the Moogoongwha satellite broadcasting signal. The transmission power was able to feed the patch dipole in series due to lay perpendicularly 8 series patch dipole on tapered slot. The patch dipole radiation pattern which fed in series power, make the main beam direction up $37^{\circ}{\sim}42^{\circ}$ within the BS/CS bandwidth. The main beam gain was measured 9.31~11.03 dBi. Using 32 elements to array the elements properly, we acquire $4{\times}8$ array structure on limited PCB board. As a result, it has been found that the new planar DBS antenna structure have high gain over 10dBi and acceptable elevation angle over 42 degree, and we can apply this result to commercial DBS reception antenna manufacturing.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.5
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• pp.748-754
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• 2000

A novel single feed wide band CP stacked microstrip antenna using crossed slots has been designed, fabricated and measured. For the single rediating element the designed 10dB return loss bandwidth is 34.5%99.45~13.54 GHz), 3dB axial ratio bandwidth is 18.7%(11.17~13.39GHz), and 6 dB gain bandwidth is 29%(10.21~13.64GHz). For the 2$\times$2 array designed using a sequential rotation method, the 10dB return loss bandwidth is 35.9%(9.69~13.94GHz), 3dB axial ratio bandwidth is 34.6GHz (9.93~14.03GHz), and 6dB gain bandwidth is 27.4%(10.35~13.6GHz). For the fabricated 8$\times$8 array antenna, the 10dB return loss bandwidth is 27.3%(10.17~13.41GHz), 3dB axial ratio bandwidth is 27.9GHz(10.1~13.4GHz), and the radiation pattern is good agreement with theory. This antenna can be used for broadband applications for communications or broadcasting in Ku band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.7
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• pp.1131-1137
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• 1999

In this paper, a novel design method of an apertured coupled microstrip patch antenna with the single feeding structure is proposed for dual resonance frequencies with mutually perpendicular polarizations. The characteristics of this antenna are experimentally investigated. In order to achieve this goal, a new type of square patch with double notches is used as a radiator and the crossed slot and the bended mictrostrip feeder are adopted for the dual polarizations in the aperture-coupled structure. For the application of the proposed antenna, a Ku-band Tx/Rx $2\times$ subarray antenna is designed and manufactured. Also, the applicability of the antenna as a ground terminal is examined through performance analysis. According to the measurement, the gain of the antenna is 10dBi at the center frequencies of Tx and Rx, the side lobe level is lower than -13dB, and the cross polarization lebel is below 17 dB.