• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.2 s.93
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• pp.128-133
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• 2005

An iris-coupled partial H-plane filter as a new type of partial H-plane filter is proposed. The proposed filter can be compared with conventional H-plane filter and uses an iris-type evanescent waveguide as a coupling structure. Filter design technique based on numerical simulation is developed to design and compare the proposed filter and H-plane filter. Designed iris-coupled partial H-plane filter has the same frequency response as that of the conventional H-plane filter while its cross section is one quarter. A good agreement between measurements and theoretical prediction is achieved.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.8 s.111
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• pp.746-752
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• 2006

In this paper, a compact partial H-plane filter with periodic structure is proposed. Guided wavelength of periodic structure' is reduced by slow wave effect. Cross-section and length of partial H-plane filter with periodic structure are considerably reduced by 75% and 30%, respectively, as compared with conventional E-plane filter. In addition, spurious responses of the bandpass filter are improved. To design bandpass filter with periodic structure, we have analyzed a periodic structure of partial H-plane waveguide and derived equations of the periodic filter. Measured results are in good agreement with simulated results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.107-113
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• 2008

This paper presents half wavelength partial H-plane filters with multiple attenuation poles using narrow H-plane slot of evanescent waveguide. The narrow H-plane slot operates as an admittance inverter o( the bandpass filter and, simultaneously, generates an attenuation pole at particular frequency. Therefore, proposed filters with attenuation poles are simply implemented without any additional coupling and extra modification of the structure. The number of attenuation poles of the filters equals to that of the H-plane slots. Moreover, proposed filters are compact waveguide filter since ones are embodied by partial H-plane waveguide which has 1/4 cross section of conventional waveguide. The third and fourth-order half wavelength filters having 4 and 5 attenuation poles, respectively, are designed in H-band and their frequency responses are confirmed by simulation and measurement.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.4
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• pp.1048-1058
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• 1996

In this paper, a small duplexer is designed and implemented using a H-plane T-junction and Transmitting/Geceiving filte with a dual mode cavity resonator for Ku-band. Transmitting(TX) filter is designed at center frequeny 12.5 GHz and Receiving(RX) filter, at center frequency 14.5 GHz. Both filters have a 100 MHz bandwidth. This duplexer is reduced to about 40% by the conventional duplexer of cavity bandpass filter structure in size. Operating characteristics of duplexer is optimized in order not to distors matching characteristics of each filter when interfaced to a H-plane T-junction. Consequently, the responses of filter with H-plane T-junction nearly coincide with that of filter itself.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.9
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• pp.15-20
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• 1997

Waveguide bandpass filters using E-plane or H-plane discontinuities have been used in many satellite communication systems. Since the transmitter and receiver of such systems tend to be getting smaller, components such as bandpass filters must also be reduced in size. In this paper, in order to reduce the waveguide, itself, of which bandpass filters consist, double plane step waveguide discontinuities are considered. They are analyzed using the mode matching method and the genralized scattering parameter of the cascaded structure is calculated. The characteristics of the bandpass filter which is designed using the reduced size waveguide is optimized by OSA90$^{TM}$. The bandpass filter has a good characteristics and smaller size than those made of the E-plane or H-plane step discontinuities.s.

• Journal of Advanced Navigation Technology
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• v.14 no.1
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• pp.11-19
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• 2010

In this paper, H-plane filtering-horn antenna operating at millimeter frequency band is proposed with embedded filter and three-layered dielectric lens for frequency selection and maintenance of main beam direction, respectively. The waveguide-typed filter and H-plane sectoral horn antenna are replaced with considerably size-reduced PCB substrate-typed filtering antenna using via fences and several posts. The waveguide-typed filter and H-plane sectoral horn antenna were designed in air-filled waveguide and then combined into size-reduced PCB substrate. For the control of the thickness of dielectric lens, single and multi dielectric lens have been employed. As a result of antenna gain, 8 and 13.5 dBi have been obtained at 41.5 GHz, respectively, from the simulations of single and multi-lens antennas.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.2
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• pp.33-39
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• 2013

In this paper, X/Ku band waveguide diplexers with H-plane T-junction for satellite communication systems is proposed and its characteristics is cinfirmed. Two frequency bands such as X(7.25 ~ 8.4 GHz) and Ku(12.25 ~ 14.5 GHz) can be separated by the proposed waveguide diplexers. A diplexers is normally including low pass filter, high pass filter and junction waveguide. To simplify the structure of the proposed diplexers, the proposed waveguide diplexers is using impedance matching technique on H-plane of the high pass filter without low pass filter. To use vertical and horizontal polarization, the proposed diplexers with orthomode transducer(OMT) characteristics is also designed. Therefore, it is confirmed that the proposed waveguide diplexers can be used as dual-band and dual-polarization diplexers for satellite communication feed systems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.55-56
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• 2018

In this paper, a method for analyzing the dielectric constant of a planar substrate is proposed. To this end, a band-stop filter was created by adding a H-shaped resonant aperture to the ground plane of a microstrip transmission line. A planar substrate of 2 mm thickness was placed behind the ground plane of the microstrip transmission line and the change of the resonant frequency with the change of the dielectric constant of the substrate was investigated. It can be seen that the change ratio of the frequency to the reference resonant frequency is larger than that of the conventional complementary split ring resonator structure.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1845-1848
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• 2003

PD(Partial Discharge) signal have the range from several kHz to several GHz. External noises don't give any interference to discerning PD signals with high frequency bandwidth between several hundreds MHz to several GHz but, in the range between several decades kHz to several MHz, are big obstacles to prevent from discriminating PD signals. Therefore, selecting appropriate filter to decrease the influence of noise is important problem. PD signals have the characteristics both short duration and non-continuous pulse train. For separating PD signals from External noises, some different filtering methods different from conventional ones are needed and wavelet filtering method was convinced to be suitable filtering method in various investigations. This paper has simulated PD signal and various noises and investigated the influences for the performance of wavelet filter by varying the components relative to designing of wavelet filter and constructed suitable one. For the purpose of convincing the performance of wavelet filter, real PDs were produced in needle to plane electrode structure. This small PD signal was mixed with external noises and filtered with wavelet filter. We have obtained apparent PD signals and noises are well suppressed by wavelet filter.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.4
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• pp.582-593
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• 1999

This paper presents the design and fabrication of the diplexer for a KOREASAT-III Ka-band satellite transponder. The transmission characteristics of the diplexer is analyzed by calculating the generalized scattering matrix using mode matching method. It is composed of 2 bandpass filters, coupled with H-plane T-junction having symmetrical inductive iris and E-plane metal insert structures. Compared with the size and weight of the Rx and Tx filter loaded with a transponders respectively, those of the diplexer can be effectively reduced. In a high power transmission, the variation of the filter characteristics is minimized by the scheme that irises are extended to the exterior of H-plane of the waveguide. This scheme needs no extra heat sinks for dissipating high power. The diplexer is designed to improve the simplification, durability and reliability by eliminating tuning screws, which have been used to compensate for the characteristics of fabricated filters. The bandpass filters of the diplexer show the insertion loss of less than 1.2 dB and the return loss in excess of 15 dB. The isolations of more than 65 dB have been achieved between Rx and Tx filter.