A New Model to Determine Passive Intermodulation Terms When Non-Contributing Carriers are Added to Classical Scenarios

[EN] This paper provides a new theoretical model for the characterization of passive intermodulation behaviour when non-contributing carriers (i.e., carriers which do not directly affect the particular non-linear contribution under analysis) are added to classical two or three carriers scenarios. According to traditional models, the power of a particular passive intermodulation frequency term is only related to the contributing carriers which combines in non-linear way to generate this term, thus the presence of additional (i.e., non-contributing) carriers should not affect to the predicted power of such an intermodulation product. However, recent laboratory tests reveal that non-contributing carriers do reduce the power of unrelated passive intermodulation terms. A heuristic model is proposed in this work to explain this effect, which shows a good matching with measured results already published in the technical literature. The study is focused in third order non-linear contributions, as being the most critical in practical applications.This work was supported in part by the Ministerio de Ciencia e Innovacion (Spanish Government) under Research and Development Project PID2019-103982RB-C41, and in part by the European Regional Development Fund.Smacchia, D.; Soto Pacheco, P.; Boria Esbert, VE.; Raboso García-Baquero, D. (2021). A New Model to Determine Passive Intermodulation Terms When Non-Contributing Carriers are Added to Classical Scenarios. IEEE Access. 9:152070-152074. https://doi.org/10.1109/ACCESS.2021.3126903S152070152074

Experimental Analysis of the Multipactor Effect With RF Pulsed Signals

© 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.The main goal of this letter is the analysis of the multipactor effect within a coaxial waveguide excited by an RF pulsed signal. The variation of the multipactor RF voltage thresholdwiththe ON interval length of the pulse has been analyzed. To reach this aim, an in-house multipactor simulation code based on the Monte-Carlo algorithm has been implemented. The numerical simulations show that the multipactor RF voltage threshold increases as the ON pulse interval diminishes. In addition, an experiment was carried out to validate the proposed theoretical model, and demonstrating the excellent agreement between the theory and the experimental data. Finally, the results are compared with the 20-gap-crossing rule used in the space standard document (ECSS-E20-1A).The work of O. Monerris Belda was supported by the European Regional Development Fund. The review of this letter was arranged by Editor A. Ortiz-Conde.Gonzalez Iglesias, D.; Monerris Belda, Ó.; Diaz, M.; Gimeno Martinez, B.; Boria Esbert, VE.; Raboso García-Baquero, D. (2015). Experimental Analysis of the Multipactor Effect With RF Pulsed Signals. IEEE Electron Device Letters. 36(10):1085-1087. doi:10.1109/LED.2015.2468068S10851087361

Efficient Design of Waveguide Manifold Multiplexers Based on Low-Order EM Distributed Models

In this paper, a new systematic technique to design manifold-coupled multiplexers in waveguide technology is proposed. The new technique uses generalized low-order electromagnetic (EM) distributed models, which constitute a half-way point between the fast, but imprecise, analytical models, and the more accurate, but costly, full-wave EM models. The method can be applied to contiguous and noncontiguous channel multiplexers, in both E-plane or H-plane configurations. This paper covers the complete design procedure for manifold multiplexers, starting from the required specifications and finishing with the physical dimensions. After explaining the general design technique for multiplexers with channel filters based on transmission-line resonators, the method is specialized for the design of classic multiplexers with circular-waveguide dual-mode filters. As a further application example, the same methodology is also used for the design of a nonconventional tuningless wideband multiplexer with a new type of rectangular waveguide filters. This paper is concluded with a comparison between simulation and measurements for the wideband multiplexer. Excellent agreement between measurements and simulations are demonstrated, thereby validating the complete design procedure.The authors would like to thank the European Space Agency (ESA) and Val Space Consortium (VSC) High Power RF Space Laboratory (A laboratory funded by the European Regional Development Fund, A way of making Europe) for financing the manufacture and experimental validation of the wideband six-channel PIM test bed.Cogollos Borras, S.; Soto Pacheco, P.; Boria Esbert, VE.; Guglielmi, M.; Brumos Vicente, M.; Gimeno Martinez, B.; Raboso García-Baquero, D. (2015). Efficient Design of Waveguide Manifold Multiplexers Based on Low-Order EM Distributed Models. IEEE Transactions on Microwave Theory and Techniques. 63(8):2540-2549. doi:10.1109/TMTT.2015.2442990S2540254963

Advanced Compact Setups for Passive Intermodulation Measurements of Satellite Hardware

(c) 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other users, including reprinting/ republishing this[EN] This paper provides the guidelines for the practical development of novel advanced test beds for passive intermodulation(PIM) measurements. The proposed test beds show high performance and are flexible, allowing for the measurement of several PIM signals of different orders, with two or more input carriers. In contrast to classic test beds for satellite hardware, based on the cascaded connection of several elements, an integrated solution involving the minimum number of hardware pieces is proposed. The result is a lower number of flanged interconnections, thus reducing residual PIM level and insertion losses. In addition, return loss degradation and harmful spurious generation in the interconnections are also avoided. Measurement test beds for conducted and radiated PIM, in both transmitted and reflected directions, are discussed, highlighting the benefits and drawbacks of each configuration. Design guidelines for the key components are fully discussed. Illustrative application examples are also reported. Finally, excellent experimental results obtained from low-PIM measurement setups, working from C-band to Ka-band, are shown, thus fully confirming the validity of the proposed configurations.This work was supported in part by the European Space Agency through several research and development contracts, in part by the Ministerio de Economia y Competitividad (Spanish Government) under Project TEC2016-75934-C4-1-R, and in part by the ESA-VSC High Power RF Space Laboratory.Smacchia, D.; Soto Pacheco, P.; Boria Esbert, VE.; Guglielmi, M.; Carceller Candau, C.; Ruiz-Garnica, J.; Galdeano, J.... (2018). Advanced Compact Setups for Passive Intermodulation Measurements of Satellite Hardware. IEEE Transactions on Microwave Theory and Techniques. 66(2):700-710. https://doi.org/10.1109/TMTT.2017.2783383S70071066

Optimized Multipactor-Resistant Wedge-Shaped Waveguide Bandpass Filters

[EN] Wedge-shaped waveguides present a certain advantage with respect to rectangular waveguides regarding their resistance to multipactor discharges. In this paper, the optimal configuration for the wedge geometry is investigated based on theoretical results, on a precise multipactor prediction tool, and on previous experience. In addition, design rules are presented, which allow us to achieve for wedge-shaped filters electrical performances comparable to the ones of rectangular waveguide filters, while at the same time improving the multipactor-free power range. As a proof of concept, two three-pole bandpass filters with equivalent electrical characteristic of 150-MHz bandwidth, centered at 12 GHz (Ku band), and the same Q factor have been designed, manufactured, and tested. The first design is based on conventional rectangular waveguide technology, while the second one has non-parallel broadside walls (wedge-shaped cross section). The multipactor power threshold and RF performance of the filters have been measured in order to validate the improvements achievable employing wedge-shaped resonators.This work was supported by the Ministerio de Ciencia e Innovacion, Spain, under Research Project TEC2010-21520-C04-01/TCM.Hueso González, J.; Raboso García-Baquero, D.; Ernst, C.; Schmitt, D.; Boria Esbert, VE.; Gimeno Martinez, B.; Taroncher Calduch, M.... (2013). Optimized Multipactor-Resistant Wedge-Shaped Waveguide Bandpass Filters. IEEE TRANSACTIONS ON PLASMA SCIENCE. 41(8):2135-2144. https://doi.org/10.1109/TPS.2013.2253134S2135214441

Prediction of multipactor breakdown for multicarrier applications: the quasi-stationary method

© 2012 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.A new prediction algorithm for multipactor breakdown determination in multicarrier signals is presented. This new algorithm assumes a quasi-stationary (QS) model based on the nonstationary theory for single-carrier signals. It determines the worst case, i.e., the combination of signal phases that yields the lowest breakdown level per carrier, using multipactor electron growth models. It considers the secondary emission yield properties of the material and the time-varying value of the multicarrier signal envelope. Several test samples have been designed and manufactured in order to assess the precision of the proposed method. The experimental results show excellent agreement with the predicted results. The QS prediction technique yields, in general, better accuracy and more relaxed breakdown levels than the existing methods.Manuscript received December 23, 2011; revised April 12, 2012; accepted April 16, 2012. Date of publication May 30, 2012; date of current version June 26, 2012. This work was supported by the European Space Agency (ESA)/European Space Research and Technology Centre (ESTEC) under RF Breakdown in Multicarrier Systems Contract 1-9918/06/NL/GLC, by the Ministerio de Ciencia e Innovacion under Programa Torres Quevedo PTQ06-2-0693, and under Research Project TEC2010-21520-C04-01.Anza Hormigo, S.; Vicente Quiles, CP.; Gil Raga, J.; Mattes, M.; Wolk, D.; Wochner, U.; Boria Esbert, VE.... (2012). Prediction of multipactor breakdown for multicarrier applications: the quasi-stationary method. IEEE Transactions on Microwave Theory and Techniques. 60(7):2093-2105. https://doi.org/10.1109/TMTT.2012.2197021S2093210560

Study of the Secondary Electron Yield in Dielectrics Using Equivalent Circuital Models

© 2018 IEEE. Personal use of this material is permitted. Permissíon from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertisíng or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.[EN] Secondary electron emission has an important role on the triggering of the multipactor effect; therefore, its study and characterization are essential in radio-frequency waveguide applications. In this paper, we propose a theoretical model, based on equivalent circuit models, to properly understand charging and discharging processes that occur in dielectric samples under electron irradiation for secondary electron emission characterization. Experimental results obtained for Pt, Si, GaS, and Teflon samples are presented to verify the accuracy of the proposed model. Good agreement between theory and experiments has been found.The authors would like to thank the European High Power Space Materials Laboratory for its contribution-a laboratory funded by the European Regional Development Fund-a way of making Europe. Many thanks to the University of Valencia (Spain) for supporting this research activity with the internal program "Assistance for temporary stays of invited researchers within the framework of the Subprogramme Attraction of Talent 2015".Bañón, D.; Socuellamos, JM.; Mata-Sanz, R.; Mercadé-Morales, L.; Gimeno Martínez, B.; Boria Esbert, VE.; Raboso García-Baquero, D.... (2018). Study of the Secondary Electron Yield in Dielectrics Using Equivalent Circuital Models. IEEE Transactions on Plasma Science. 46(4):859-867. https://doi.org/10.1109/TPS.2018.2809602S85986746

Multipactor radiation analysis within a waveguide region based on a frequency-domain representation of the dynamics of charged particles

A technique for the accurate computation of the electromagnetic fields radiated by a charged particle moving within a parallel-plate waveguide is presented. Based on a transformation of the time-varying current density of the particle into a time-harmonic current density, this technique allows the evaluation of the radiated electromagnetic fields both in the frequency and time domains, as well as in the near- and far-field regions. For this purpose, several accelerated versions of the parallel-plate Green’s function in the frequency domain have been considered. The theory has been successfully applied to the multipactor discharge occurring within a two metal-plates region. The proposed formulation has been tested with a particle-in-cell code based on the finite- difference time-domain method, obtaining good agreement.The authors would like to thank ESA/ESTEC for having funded this research activity through the Contract “RF Breakdown in Multicarrier Systems” ͑Contract No. 19918/06/NL/GLC͒

Analysis of multipactor RF breakdown in a waveguide containing a transversely magnetized ferrite

In this paper, the multipactor RF breakdown in a parallel-plate waveguide partially filled with a ferrite slab magnetized normal to the metallic plates is studied. An external magnetic field is applied along the vertical direction between the plates in order to magnetize the ferrite. Numerical simulations using an in-house 3D code are carried out to obtain the multipactor RF voltage threshold in this kind of structures. The presented results show that the multipactor RF voltage threshold at certain frequencies becomes considerably lower than for the corresponding classical metallic parallel-plate waveguide with the same vacuum gap.This work was supported by the European Space Agency (ESA) under Novel Investigation in Multipactor Effect in Ferrite and other Dielectrics used in high power RF Space Hardware Contract AO 1-7551/13/NL/GLC, and partially by the Spanish Government (under coordinated R&D projects TEC2013-47037-C5-R and TEC2014-55463-C3-3-P)

Multipactor mitigation in coaxial lines by means of permanent magnets

The main aim of this paper is the analysis of the feasibility of employing permanent magnets for the multipactor mitigation in a coaxial waveguide. First, the study of a coaxial line immersed in a uniform axial magnetic field shows that multipactor can be suppressed at any RF if the external magnetic field is strong enough. Both theoretical simulations and experimental tests validate this statement. Next, multipactor breakdown of a coaxial line immersed in a hollow cylindrical permanent magnet is analyzed. Numerical simulations show that multipactor can be suppressed in a certain RF range. The performed experimental test campaign demonstrates the capability of the magnet to avoid the multipactor electron multiplication process.This work was supported by the European Regional Development Fund-A Way of Making Europe. The review of this paper was arranged by Editor R. Carter.Gonzalez Iglesias, D.; Pérez Pastor, AM.; Anza Hormigo, S.; Vague Cardona, JJ.; Gimeno Martinez, B.; Boria Esbert, VE.; Raboso García-Baquero, D.... (2014). Multipactor mitigation in coaxial lines by means of permanent magnets. IEEE Transactions on Electron Devices. 61(12):4224-4231. doi:10.1109/TED.2014.2361172S42244231611