• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.12
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• pp.3205-3214
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• 1996

In this paper, the microstrip phased array antennas with coupling-slots for the base station of mobile communication is proposed and anlyzed with accurate analysis method which is based on both reciprocity principle and full-wave analysis. The basis functions used for the numerical analysis are determined depending upon the accuracy, convergence properties of the solution, and the computation time. The patch uses 3 EB mode and the slot uses IPWS mode. The designed phased array antenna has 8 slot-coupled microstrip patch array elements and the beam scanning capability is obtained by using the 4-bit PIN-diode phase shifters as switching devices which are consisted of the loaded line phase shifters for 30.deg. and 60.deg. and the reflection type phase shifters for 90.deg. and 180.deg. repectively. The 4-bits phase shifters which aremade by connecting each phase shifter have about 2.deg.-3.deg. phase errors and their insertion loss are about 3dB for each phase state. The fabricated 8-element phased array antenna with 4-bits phase shifters provides 12.deg.-14.deg. beamwidths depending on the scanning angle and is capable of scanning its beam to .+-.45.deg. with 9.deg. intervals, and the gain 12dBi. The overall results show that the slot-coupled phased array antenna has great advantages of wideband, high gain and reduced spurious radiation. Also, the antenna can be made small and thin. Furthermore, the scanning property of this antenna allows for its application in several areas, such as mobile communication system and PCS.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.8
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• pp.684-692
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• 2016

In this paper, a non-offset longitudinal shunt slot excited by an asymmetry compound iris on the broad wall of a rectangular waveguide is presented as an element for a waveguide slot-array antenna(WSAA). By properly adjusting the iris dimension, a resonance of the slot at a desired frequency can be achieved. The proposed resonant slot has some advantageous properties, such as a wide range of normalized resonant conductance, and minimum change of phase in the waveguide at the resonance. In addition, when the slots are arrayed for a waveguide slot antenna, the unwanted cross-polarization level can be reduced because each slot is placed in a straight line. A $8{\times}1$ WSAA with -20 dB side-lobe level(SLL) is designed, fabricated, and tested experimentally. The measured results are well agreed with the simulated ones and have an SLL of -18.13 dB and a cross-polarization level of -48.85 dB at 9.41 GHz, which was improved by about 15 dB of that of the conventional longitudinal slot array antenna.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.4
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• pp.353-359
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• 2004

In this paper, the single-layer slotted waveguide array antenna is designed, which consists of two par the slot plate and the structure of waveguide. The key difficulty in mass production is the realization of perfect electrical contact between the two parts. Therefore the single-layer slotted waveguide array antenna is presented with a dumbbell patch and a choke. The choke can prevent from the leakage between the slot plate and waveguide, while the choke in the adjacent waveguide incurs space dissipation. To reduce the spacing of antennas about a dumbbell patch is utilized. the 16${\times}$16 array antenna gain of 27.2 ㏈ with 45 % aperture efficiency is obtained.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.8
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• pp.1598-1603
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• 2003

A microstrip array antenna is designed and tested for satellite broadcasting receptions. The Sierpinski equilateral triangular patch and SSFIP(slot­strip­foam­inverted patch) structures are used. The Sierpinski geometry is composed of 3 equilateral triangular patch and is easy to generate a circular polarization by sequential rotation array techniques. This 1${\times}$3 Sierpinski equilateral triangular patch antenna is extended to 8${\times}$2 array antenna for satellite broadcasting receptions. The measurement results of the reflection coefficients and the radiation patterns of the manufactured array antenna show good agreements with the simulation results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.9B
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• pp.1511-1517
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• 2000

A new slot-coupled back-to-back microstrip array antenna is proposed for using in the IMT-2000 base station or repeater antenna. This antenna is composed of symmetrical SSAIP(Strip Slot, Air Inverted Patch) It has bidirectional radiation pattern in horizontal plane and 22.5$^{\circ}$main beam squint in vertical plane. The analysis is based on the cavity model and the design is achieved using Ensemble. Experimental results for the radiation pattern and the return loss have shown that the direction of the main beam is about 21$^{\circ}$and the impedance bandwidth is approximately 22.9% Thus the proposed antenna is able to operate over both uplink and downlink frequencies in IMT-2000.

• ETRI Journal
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• v.26 no.3
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• pp.262-264
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• 2004

We investigate the characteristics of a wideband and high-gain cavity-backed slot antenna in terms of the reflection coefficients, radiation patterns, and gain. A cavity-backed slot antenna structure includes baffles, reflectors, and thick ground planes. The measured gain and bandwidth of a 10-dB return loss in a cavity-backed $2{\times}2$ array slot antenna with $h_1=2 $mm, d=2 mm are 15.5 dBi and nearly 27%, respectively, at 42 GHz. Baffles and reflectors are used to increase antenna gain, thus reducing the coupling among the slots on the thick ground plane.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2003.10a
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• pp.49-52
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• 2003

A microstrip array antenna is designed and tested for satellite broadcasting receptions. The Sierpinski equilateral triangular patch and SSFIP(slot-strip-foam-inverted patch) structures are used. This 1$\times$3 Sierpinski equilateral triangular patch antenna is extended to 8$\times$2 array antenna for satellite broadcasting receptions. The measurement results of the reflection coefficients and the radiation patterns of the manufactured array antenna show good agreements with the simulation results.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.21 no.1
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• pp.73-80
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• 2022

Sensors are applied to small aviation platforms for various purposes. Radio frequency (RF) antennas, which are representative sensors, are available in many forms but require the application of slot array RF antennas to ensure high performance and designation. Slot RF array antennas are applied to dip brazing techniques, but the yield and production time are determined by the proficiency of production personnel in a labor-intensive form. Unmanned aerial vehicles or drones, which are representative small aviation platforms, are continuously exposed to various random vibrations because propellers and multiple power sources are used in them. In this study, the fatigue life of slot array RF antennas applied with additive manufacturing was evaluated through the cumulative damage method (Miner's rule) in a vibration environment with a small aviation platform. For the evaluation, an S N curve obtained from a fatigue strength test was used.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.51 no.8
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• pp.375-381
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• 2002

A rigorous analysis of a broad wall slot array is presented. The slot is longitudinal and offset from the center line in the rectangular waveguide. Pertinent integral equations are developed, taking into account finite wall thickness. The mothed of moment with entire basis function is used to solve a pair of coupled-integral equations, derived from the electromagnetic boundary conditions using modified Green's function, to find the tangential electric field on the upper and lower surfaces of the slot. Numerical results for resonant length and scattering parameters of the slots are Presented over a range of offset. Computed results are compared with experimental result.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.4
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• pp.357-365
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• 2013

The 4 by 4 series slot sub-array antenna is proposed using substrate integrated waveguide(SIW) technology for 35 GHz of Ka band application. The proposed antenna is realized with multi-layered structure for compact size and easy integration features. 4 by 4 radiating slots are arrayed on top PCB with equal spacing and the feeding SIWs are arranged on middle and bottom PCBs for uniform power distribution. The multi-layered antenna is realized using RT/Duroid 5880 that has dielectric constant of 2.2 and the total antenna size is $750.76mm^2$. The individual parts such as radiators and feeding networks are simulated using full-wave simulator CST MWS. Furthermore, the total sub-array antenna also fabricated and measured the electrical performances such as impedance bandwidth under the criteria of -10 dB(490 MHz), maximum gain(18.02 dBi), sidelobe level(SLL)(-11.0 dB), and cross polarization discrimination (XPD)(-20.16 dB).