• Journal of electromagnetic engineering and science
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• v.6 no.4
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• pp.217-221
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• 2006

Multipactor-free S-band duplexer based on inter-digital cavity type filter is proposed and demonstrated by in-house mulitpactor test facility for satellite RF components. Multipactor sensitivity of designed duplexer is analyzed by checking it out the maximum field accumulated region inside duplexer and calculating the electric field intensities at each resonator using 3D EM simulation in order to restrict the minimum gap distance as 2.5 mm which handles 43.13 dBm RF input power. Multipactor threshold was finally detected at 44 dBm in experiment for pulse mode test. The developed multipactor test method is cost effective, simple structure and gives a good agreement compared with the previous high cost MP test methodologies.

• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.83-91
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• 2007

An experimental verification of multipactor(MP) discharge for S-band diplexer as a sample DUT for space application by an in-house MP test facility is proposed. The designed diplexer having two BPFs for Rx and Tx is applied to a design of five pole inter-digital cavity type band pass filter with chebyshev response, it has 2.7 % bandwidth centered at 2.232 and 2.055 GHz for Rx, Tx, respectively. To avoid the MP discharge, the accurate design and analysis methods based on 3D EM field analysis are considered. The proposed in-house MP test facility consists of a phase detecting system using a doubly balanced mixer as a simple, low cost and real time MP test method compared with results of previously well-known MP detection systems as cross reference methods. The calculated MP threshold RF input power is 43.13 dBm. The measured one is 43 dBm and 44 dBm for CW, pulsed mode test, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.1
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• pp.49-60
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• 2017

In this paper, we presented the result of the study on high-power handling capability of the X-band circular waveguide cavity filter configured at the output of high power amplifier(120 W) for geostationary satellites. The dual mode circular waveguide cavity filter with 6th order is selected and the physical model of the filter is designed after determination of the size of resonator from mode chart. Multipactor margin analysis is performed by the SEM method and the VMF method. The result shows that the VMF method predicts lower multipactor breakdown thresholds than the SEM method. Evaluating the multipactor margin obtained by the VMF method to ECSS criteria, we could decide to perform multipactor test. The multipactor test conducted in ESA facility shows that multipactor did not occur even until the RF power increased up to 540 W. In consequence, by both analysis and test, we could verify that the X-band circular waveguide cavity filter has the sufficient high-power handling capability to operate on orbit.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.65-68
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• 2017

In this paper, a multipactor test for the space qualification model of the X-band dual-mode high-power channel filter for high-speed data transmission of geostationary satellite observation payloads was conducted and compared with the 8 dB margin required for design. It was confirmed that analytically required margins were met through testing and that satisfactory test results were obtained. The design and test of the multipactor are tested according to the ECSS standard. Based on this, it is suggested that if the margin of design is sufficiently secured, it can be used in the development of the filter for space qualification model without any test.

• Bulletin of the Korean Space Science Society
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• 2004.10b
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• pp.360-363
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• 2004

This review is concerned with the MP (multipactor) phenomena of the diplexer for RFDU DM of next generation satellite. The MP discharge is serious problems to design RF components in space applications such ase damage of physical structure, performance degradation, and mission failure of the satellite. In this work, we employed the 3D finite element method (FEM) to calculate the critical gap points and adopted ESTEC curve, MP susceptibility zone, to analyze the maximum handling RF power in the diplexer. And this work also recommends that one should design the tx filter of the diplexer which is more wider bandwidth upto the points to escape the ears of the group delay especially the cavity type of RF components in space applications.

• Bulletin of the Korean Space Science Society
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• 2006.04a
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• pp.104-104
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• 2006

• Journal of Satellite, Information and Communications
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• v.12 no.3
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• pp.80-85
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• 2017

In this paper, a mircrowave breakdown of X-band circular waveguide cavity filter, which occurred during ground test, was introduced, and electro-magnetic field simulation results to identify a root cause, and the analysis of possibility of its occurrence on orbit operation were presented. Filter modeling for simulation was conducted with a commercial tool (FEST3D), and electric fields inside the filter were monitored at the input of 1 W continuous wave. In our observation, strong electric field intensities were monitored on the tuning screws especially at the input of band-edge frequencies. The threshold power levels for the breakdown were also estimated and compared with the input power levels actually injected to the filter. From this estimation, we could figure out that the power exceeding the breakdown threshold was injected to the filter so that strong electric fields were generated and temperature increased high, and this became a root cause of the electrical short. Our further analysis showed that this kind of microwave breakdown is not likely to occur on orbit operation, and multipactor is expected not to occur at the input of band-edge frequencies. As a measure to prevent the microwave breakdown, we suggested to avoid the injection of band-edge frequencies and inject lower power levels to the filter.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.9
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• pp.755-760
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• 2013

The electromagnetic compatibility and its effects, and the system design considerations in space environment are studied in this paper using Multipator. The system level EMC test results of digital channel amplifier(DCAMP), its affects upon the H/W improving methods regarding its over exceed value of EMC specification are discussed. These analysis values and test results can be used as the criteria for the selection of EMC requirements and of the MILSATCOM system design.

• Journal of Satellite, Information and Communications
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• v.10 no.3
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• pp.131-136
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• 2015

In this paper, prior to the flight model X-band dual-mode circular cavity filter required for the high power transmission of the observation payload in the geostationary satellite, the development model are designed and analyzed to show the analytical multipactor requirement margin. First of all, the multipaction breakdown power sensitivities were analyzed by changing the iris width and thickness within the filter, and through that the iris width and thickness was selected and then the multipaction threshold powers over the frequencies within the bandwidth were analyzed and the required margin of 8 dB was obtained. Also for the high power transmission filter, another important phenomena known as corona breakdown are analyzed for the iris width and thickness changes. Finally the development model manufactured was tested and the results met the key requirements.