• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.9 s.112
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• pp.836-844
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• 2006

In this paper, we designed and fabricated the wideband probe with double ridged waveguide for Near-field Measurement. An exponential taper ridge in the rectangular waveguide was implemented for wideband impedance matching. It has wideband characteristics and its measured impedance bandwidth ratio is approximately 2.2:1 from 8.2 GHz to 18 GHz for $VSWR\leq2.2$. It maintains about the same radiation pattern over the entire bandwidth and has more than 4.5 dBi peak radiation gain. Our designed probe was applied to near-field measurement. A good agreement has been found between simulated and measured results.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2001.11a
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• pp.198-201
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• 2001

L자형 루프를 이용하여 주파수대역이 6-18 GHz인 동축-이중릿지도파관 변환기를 상용 소프트웨어인 HFSS를 이용하여 설계한 후 제작하였다. L자형 루프는 동축-구형도파관 변환기에 이미 이용되고 있는 구조로써, 이를 동축-이중릿지도파관 변환기에 적용한 것이다. 제작 후 측정결과 대역폭이 6-18 GHz로 3:1 이상을 만족하며, 최대 삽입손실이 -1.52 dB 이었다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.8
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• pp.950-957
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• 2012

In this paper, a small round-ended slot loaded by double ridges on the broad wall of a rectangular waveguide is presented as an element for a waveguide slot-array antenna(WSAA). By properly adjusting the ridge dimension, a resonance of the slot at a desired frequency can be achieved. The resonant length of the proposed slot is about $0.26{\lambda}_0$(free space wave length) at the resonance frequency. The proposed resonant slot has some advantageous properties, such as small size, small resonant conductance, and short and stable resonant slot length. In addition, the characteristics of the slots are slightly affected by the adjacent elements when the slots are arrayed for a waveguide slot antenna. A $4{\times}1$ 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 -15.9 dB and a half-power beam width of $110.2^{\circ}$ in the E-plane and $21.2^{\circ}$ in the H-plane, respectively, at 9.41 GHz.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.565-568
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• 2007

In this paper, we designed and fabricated a broadband probe with a double-ridged waveguide for broadband near-field measurements. An exponentially tapered ridge in the rectangular waveguide and a novel waveguide transition were used for broadband impedance matching. The probe has broadband characteristics and its measured impedance bandwidth is approximately 123% (4.17:1) in the range 12.0-50 GHz for standing wave ratios (SWR) < 3.0. The peak radiation gain range and nominal radar cross-section (RCS) are 5.7-14.3 dBi. The performance of this probe was verified using the measured results and is in good agreement with the simulated results.