• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.334-341
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• 2016

In this paper, the study of a waveguide aperture-coupled feed-structured antenna has been conducted for the purpose of applying it to a wireless back-haul system sufficient for high-capacity gigabits-per-second data rates. For this study, a $32{\times}32$ waveguide slot sub-array antenna with a corporate-feed structure was designed and produced. Also, this antenna is used at 57 GHz to 66 GHz in the V-band. The construction of the antenna is a laminated form with radiating parts (outer groove and slot, cavity), a coupled aperture, and feeds in each. The antenna was designed with HFSS, which is based on 3D-FEM, produced with aluminum processed by a precision-controlled milling machine, and assembled after a silver-plating process. The measurement result from analysis of the characteristics of the antenna shows that return loss is less than -12 dB, VSWR < 2.0, and a wide bandwidth ranges up to 16%. An overall first side lobe level is less than -12.3 dB, and a 3 dB beam width is narrow at about $1.85^{\circ}$. Also, antenna gain is 38.5 dBi, offering high efficiency exceeding 90%.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.11
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• pp.70-77
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• 1996

In this paper, a modifed TE$_{113}$/TM$_{012}$ triple-mode bandpass filter is implemented by using a modified inter-cavity iris in which the number of slots are reduced upto 50%. In a coventioanl iris two prirs of slot apertures are used to independently couple three resonant modes between two adjacent cavities. However, if transverse magnetic polarizability of a pair of veritcal slot apertures is used to control weak horizontal TE$_{h}$-TE$_{h}$ mode coupling, the width of novel iris slots would substitute for the slot length of the conventional iris, causing to eliminate the horizontal slot apertures. The measured data of two filters, which are the modified filter and ocnventional one, are compared. Experimental result shows that the characteristics of the novel triple-mode filter matches well that of the conventional filter.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.9
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• pp.63-69
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• 2007

The directivity of crossed waveguide directional coupler is generally decreased according as coupling coefficient of it increase. In this paper, the geomertical parameters of crossed slot pair for directivity improvement is modified and the formulas for design of it are proposed. The crossed waveguide directional coupler designed upon the formulas is fabricated with the WR42 waveguide in K-band. The measured results show that the coupling coefficient is 21.5 dB and directivity is minimum 23.9 dB over the operating frequency from 18GHz to 26.5GHz.

• Journal of Satellite, Information and Communications
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• v.2 no.2
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• pp.10-15
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• 2007

Small size and low profile antenna for mobile vehicular-top-mounted is needed in satellite communication services such as DBS, Satellite Internet and VSAT. In middle latitudes, the development of an array antenna which has the conformal, low profile and 45 degree beam tilted configuration, and has the high gain with sharp beamwidth, low sidelobe and low loss is required for Ku-band satellite communication. In this paper, in order to meet with these performances, an array antenna consisting of the vertical polarized waveguide longitudinal slots based on the leaky-wave mode of traveling wave antenna is proposed. An array antenna consisting of 16 leaky-wave elements is showing 30 dBi of gain, 4.9 degree of beamwidth, below than -20 dB of sidelobe level, 45 degree of beam tilt angle in center frequency. Feed network designed by waveguide cooperated feed shows good performance of wideband and low loss.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2351-2358
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• 2014

In this paper, a design method for a compact CPW-fed slot antenna using SRRs is studied. The structure of the proposed slot antenna is a rectangular slot antenna loaded with SRR conductors inside the slot to reduce the antenna size. Optimal design parameters are obtained by analyzing the effects of the gap between the SRR conductors and slot, and the width of the SRR conductors on the input VSWR characteristic. The optimized compact slot antenna operating at 2.45 GHz band is fabricated on an FR4 substrate with a dimension of 36 mm by 30 mm. The length of the proposed compact slot antenna is reduced to 14.3% compared to that of a conventional rectangular slot antenna. Experiment results show that the antenna has a desired impedance characteristic with a frequency band of 2.4-2.49 GHz for a VSWR < 2, and measured gain of 2.3 dBi at 2.45 GHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.1
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• pp.19-25
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• 2015

In this paper, a design method for a CPW-fed slot antenna for harmonic suppression is studied. The structure of the proposed slot antenna is a rectangular slot antenna appended with stepped impedance resonators (SIRs) at both ends of the slot symmetrically. Optimal design parameters are obtained by analyzing the effects of the length and width of the SIRs on the input reflection coefficient. The optimized harmonic-suppressed slot antenna operating at 2.45 GHz WLAN band is fabricated on an FR4 substrate with a dimension of 42 mm by 30 mm. The slot length of the proposed harmonic-suppressed slot antenna is reduced to 33.3% compared to that of a conventional rectangular slot antenna owing to the appended SIRs. Experiment results show that the antenna has a desired impedance characteristic with a frequency band of 2.39-2.49 GHz for a VSWR < 2, and a measured gain of 2.5 dBi at 2.45 GHz.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.157-158
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• 2014

In this paper, a design method for a compact CPW-fed slot antenna using SRRs(split-ring resonators) is studied. The structure of the proposed slot antenna is a rectangular slot antenna loaded with SRR conductors inside the slot to reduce the antenna size. Optimal design parameters are obtained by analyzing the effects of the gap between the SRR conductors and slot, and the width of the SRR conductors on the input reflection coefficient characteristic. The optimized compact slot antenna operating at 2.45 GHz band is fabricated on an FR4 substrate with a dimension of 36 mm by 30 mm. The length of the proposed compact slot antenna is reduced by 14.3% compared to that of a conventional rectangular slot antenna. Experiment results show that the antenna has a desired impedance characteristic with a frequency band of 2.4-2.49 GHz for a VSWR < 2.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.5
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• pp.24-32
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• 1998

Spatial green's functions for a horizontal magnetic dipole in a parallel-plate waveguide are expressed in an improved closed-form with two-level approximation of the spectral green's functions. The results evaluated by the present closed-from green's function with two-level approximation are compard with those obtained the previous closed-form green's function with one-level approximation. The present results are observed to be more acurate than the previous results over wide frequency range as well as whole spatial range. The combination of the present closed-form green's functions and the moment mehtod may help in analyzing the problem of EMP coupling through an aperture into a parallel-plat waveguide and the microstrip slot antenna with a reflector.

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.5
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• pp.32-37
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• 1989

The design method of the center-fed resonant type slotted waveguide antenna using the Dolph-Tschebyscheff array is presented. Slot admittances are obtained by empirical and theoretical method since the effect of mutual coupling between slots is included. We design a slotted waveguide antenna which has 1.8ft. length and operates on 9.4GHz. The experimental results of the antenna show that its gain, maximum sidelobe level and half power beam-width are 25.5dB, -22dB and 3.6deg., respectively.

• Journal of electromagnetic engineering and science
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• v.10 no.3
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• pp.175-178
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• 2010

In this paper, a millimeter-wave multi-beam antenna is studied by rotating the antipodal linear tapered slot antenna(ALTSA) with respect to a center is successfully designed. In order to lowering the SLL and enhancing the isolation between the ALTSA elements, a row of metallic via is inserted between the ALTSAs. A 9 beams antenna is designed and experimented at Ka band. The measured and simulated results agree well with each other. The antenna can provide horizontal wide angle coverage up to ${\pm}62^{\circ}$. The gain of each beam can achieve about 12.5 dB. The mutual coupling between ports is all below 20 dB.