Long-term multipactor discharge in multicarrier systems

[EN] A new mechanism of long-term multipactor in multicarrier systems is studied employing both analytical and numerical methods. In particular, the investigation is focused on the impact that a realistic secondary emission yield at low energies produces on the development of long term multipactor. A novel analytical model for this interperiod charge accumulation is presented using the traditional multipactor theory for parallel plates, and approximating the multicarrier signal as a single-carrier signal modulated by a pulsed signal envelope. The analytical predictions are verified by numerical simulations for a typical rectangular waveguide. The analytical and numerical results demonstrate that the susceptibility of the system to develop a long-term multipactor discharge increases with higher values of low-energy secondary emission yield.The authors would like to thank ESA/ESTEC for having funded this research activity through the Contract “RF Breakdown in Multicarrier Systems” (19918/06/NL/GLC).Anza Hormigo, S.; Vicente Quiles, CP.; Gimeno Martinez, B.; Boria Esbert, VE.; Armendariz, J. (2007). Long-term multipactor discharge in multicarrier systems. Physics of Plasmas. 14(8):1-8. doi:10.1063/1.2768019S1814

EM Based Synthesis and Design of Bandpass Waveguide Filters Including Manufacturing Effects with FEST3D

This article aims at the industry interest on automated design tools that are able to take into account manufacturing effects. First, an efficient design strategy for bandpass waveguide filters including the rounded corners arising from low-cost manufacturing procedures is presented. This technique is based on a recent enhanced prototype and synthesis methodology able to consider the real structure parts. Using the resulting electromagnetic (EM)-based synthesis technique, an excellent structure is extracted, which requires, at most, only a slight final EM optimization. Second, this article presents analytical expressions providing error estimates for the different filter performances in terms of manufacturing tolerances. From such expressions, designers can determine the tolerance to be requested for a tuning-less implementation. Moreover, they can also be used to set the convergence criterion for the synthesis procedure. A fully automated design tool of bandpass waveguide filters able to consider manufacturing impairments has been developed and integrated in the commercial software Full-wave EM Simulation Tool 3D (FEST 3D)The authors thank Mrs. Eva Tarin, Mr. Oscar Monerris, and Mr. Jaime Armendariz for their work on the integration of the synthesis tool for H-plane waveguide filters in FEST 3D. This work was supported by Ministerio de Educacion y Ciencia, Spanish Government, under the Research Project ref. TEC2010-21520-C04-01.Soto Pacheco, P.; Boria Esbert, VE.; Carceller Candau, C.; Vicente Quiles, CP.; Gil Raga, J.; Gimeno Martinez, B. (2012). EM Based Synthesis and Design of Bandpass Waveguide Filters Including Manufacturing Effects with FEST3D. International Journal of RF and Microwave Computer-Aided Engineering. 22(1):93-103. https://doi.org/10.1002/mmce.2058893103221Reiter, J. M., & Arndt, F. (1995). Rigorous analysis of arbitrarily shaped H- and E-plane discontinuities in rectangular waveguides by a full-wave boundary contour mode-matching method. IEEE Transactions on Microwave Theory and Techniques, 43(4), 796-801. doi:10.1109/22.375226Zhou, J., Duan, B., & Huang, J. (2010). Influence and tuning of tunable screws for microwave filters using least squares support vector regression. International Journal of RF and Microwave Computer-Aided Engineering, 20(4), 422-429. doi:10.1002/mmce.20447Nikolova, N. (2008). Electromagnetic software in microwave engineering [Guest Editorial]. IEEE Microwave Magazine, 9(6), 10-12. doi:10.1109/mmm.2008.929880Boria, V. E., Gimeno, B., Marini, S., Taroncher, M., Cogollos, S., Soto, P., … Gil, J. (2007). Recent advances in modeling, design, and fabrication of microwave filters for space applications. International Journal of RF and Microwave Computer-Aided Engineering, 17(1), 70-76. doi:10.1002/mmce.20199Kozakowski, P., & Mrozowski, M. (2002). Gradient-based optimization of filters using FDTD software. IEEE Microwave and Wireless Components Letters, 12(10), 389-391. doi:10.1109/lmwc.2002.804561Boria, V. E., Bozzi, M., Bruni, F., Cogollos, S., Conciauro, G., Gimeno, B., & Perregrini, L. (2003). Efficient analysis of in-line waveguide filters and frequency-selective surfaces with stepped holes. International Journal of RF and Microwave Computer-Aided Engineering, 13(4), 306-315. doi:10.1002/mmce.10087Morro, J. V., Esteban, H., Boria, V. E., Bachiller, C., & Belenguer, A. (2008). Optimization techniques for the efficient design of low-cost satellite filters considering new light materials. International Journal of RF and Microwave Computer-Aided Engineering, 18(2), 168-175. doi:10.1002/mmce.20264Hunter, I. (2001). Theory and Design of Microwave Filters. doi:10.1049/pbew048eSoto, P., Tarin, E., Boria, V. E., Vicente, C., Gil, J., & Gimeno, B. (2010). Accurate Synthesis and Design of Wideband and Inhomogeneous Inductive Waveguide Filters. IEEE Transactions on Microwave Theory and Techniques, 58(8), 2220-2230. doi:10.1109/tmtt.2010.2052668Morini, A., Venanzoni, G., & Rozzi, T. (2006). A new adaptive prototype for the design of side-coupled coaxial filters with close correspondence to the physical structure. IEEE Transactions on Microwave Theory and Techniques, 54(3), 1146-1153. doi:10.1109/tmtt.2005.864112Morini, A., Venanzoni, G., Farina, M., & Rozzi, T. (2007). Modified Adaptive Prototype Inclusive of the External Couplings for the Design of Coaxial Filters. IEEE Transactions on Microwave Theory and Techniques, 55(9), 1905-1911. doi:10.1109/tmtt.2007.904329Cogollos, S., Marini, S., Boria, V. E., Soto, P., Vidal, A., Esteban, H., … Gimeno, B. (2003). Efficient modal analysis of arbitrarily shaped waveguides composed of linear, circular, and elliptical arcs using the BI-RME method. IEEE Transactions on Microwave Theory and Techniques, 51(12), 2378-2390. doi:10.1109/tmtt.2003.819776Levy, R. (1967). Theory of Direct-Coupled-Cavity Filters. IEEE Transactions on Microwave Theory and Techniques, 15(6), 340-348. doi:10.1109/tmtt.1967.1126471Balasubramanian, R., & Pramanick, P. (1999). Computer aided design ofH-plane tapered corrugated waveguide bandpass filters. International Journal of RF and Microwave Computer-Aided Engineering, 9(1), 14-21. doi:10.1002/(sici)1099-047x(199901)9:13.0.co;2-

Multipactor susceptibility charts for ridge and multiridge waveguides

“© 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.”The aim of this paper is to study the multipactor radio-frequency breakdown voltage in several ridge and multiridge waveguide configurations. First, multipactor susceptibility charts for several types of ridged waveguides have been computed using the commercial software FEST3D. Next, these charts have been used to predict multipactor threshold values for a bandpass filter and a quasi-low-pass filter both containing ridge waveguide sections. Furthermore, multipactor simulations using FEST3D are carried out to calculate the multipactor threshold of the aforementioned structures. A good agreement between predictions and simulations has been found for both filter examples.Gonzalez Iglesias, D.; Soto Pacheco, P.; Anza Hormigo, S.; Gimeno Martinez, B.; Boria Esbert, VE.; Vicente Quiles, CP.; Gil Raga, J. (2012). Multipactor susceptibility charts for ridge and multiridge waveguides. IEEE Transactions on Electron Devices. 59(12):3601-3607. doi:10.1109/TED.2012.2215611S36013607591

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

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

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

Multipactor Effect Characterization of Dielectric Materials for Space Applications

[EN] The objective of this paper is to advance the state of the art in the characterization of the multipactor effect in dielectric materials. The materials studied are the most commonly used dielectrics in space applications, namely, Alumina, Rexolite, Rogers RT5870, Rohacell, Teflon, and Ultem 1000. In this paper, a new family of coaxial waveguide components, covering the L- and S-bands, with a wideband, low-pass response has been designed, and six different prototypes have been specifically optimized and manufactured. The six prototypes have then been used to simulate and measure the multipactor breakdown susceptibility charts for the six dielectric materials investigated. Finally, the simulation results are compared with the results of the measurement campaign indicating good agreement.This work was supported in part by the European Space Agency through Research Project "Novel Investigation in Multipactor Effect in Ferrite and Other Dielectrics Used in High Power RF Space Hardware" under Grant AO 1-7551/13/NL/GLC and in part by MINECO (Spanish Government) through Research and Development Project under Grant TEC2016-75934-C4-1-R. This paper is an expanded version from the IEEE MTT-S International Microwave Workshop Series on Advanced Materials and Processes IMWS-AMP 2017, Pavia, Italy, September 20-22, 2017.Vague Cardona, JJ.; Melgarejo-Lermas, JC.; Guglielmi, M.; Boria Esbert, VE.; Anza Hormigo, S.; Vicente Quiles, CP.; Moreno Cambroreno, MDR.... (2018). Multipactor Effect Characterization of Dielectric Materials for Space Applications. IEEE Transactions on Microwave Theory and Techniques. 66(8):3644-3655. https://doi.org/10.1109/TMTT.2018.2845869S3644365566

An analytical model to evaluate the radiated power spectrum of a multipactor discharge in a parallel-plate region

This paper is aimed at studying the electromagnetic radiation pattern of a multipactor discharge occurring in a parallel-plate waveguide. The proposed method is based on the Fourier expansion of the multipactor current in terms of timeharmonic currents radiating in the parallel-plate region. Classical radiation theory combined with the frequency domain Green’s function of the problem allows the calculation of both the electric and the magnetic radiated fields. A novel analytical formula for the total radiated power of each multipactor harmonic has been derived. This formula is suitable for predicting multipactor with the third-harmonic technique. The proposed formulation has been successfully tested with a particle-in-cell code

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

Highly efficient full-wave electromagnetic analysis of 3D arbitrarily-shaped waveguide microwave devices using an integral equation technique

A novel technique for the full-wave analysis of 3-D complex waveguide devices is presented. This new formulation, based on the Boundary Integral-Resonant Mode Expansion (BI-RME) method, allows the rigorous full-wave electromagnetic characterization of 3-D arbitrarily shaped metallic structures making use of extremely low CPU resources (both time and memory). The unknown electric current density on the surface of the metallic elements is represented by means of Rao-Wilton-Glisson basis functions, and an algebraic procedure based on a singular value decomposition is applied to transform such functions into the classical solenoidal and nonsolenoidal basis functions needed by the original BI-RME technique. The developed tool also provides an accurate computation of the electromagnetic fields at an arbitrary observation point of the considered device, so it can be used for predicting high-power breakdown phenomena. In order to validate the accuracy and efficiency of this novel approach, several new designs of band-pass waveguides filters are presented. The obtained results (S-parameters and electromagnetic fields) are successfully compared both to experimental data and to numerical simulations provided by a commercial software based on the finite element technique. The results obtained show that the new technique is specially suitable for the efficient full-wave analysis of complex waveguide devices considering an integrated coaxial excitation, where the coaxial probes may be in contact with the metallic insets of the component.This work was supported by the Ministerio de Economia y Competitividad, Spanish Government, under the Research Projects TEC2013-47037-C5-1-R and TEC2013-47037-C5-4-R.Vidal Pantaleoni, A.; San Blas Oltra, ÁA.; Quesada Pereira, FD.; Pérez Soler, FJ.; Gil Raga, J.; Vicente Quiles, CP.; Gimeno Martinez, B.... (2015). Highly efficient full-wave electromagnetic analysis of 3D arbitrarily-shaped waveguide microwave devices using an integral equation technique. Radio Science. 50(7):642-655. https://doi.org/10.1002/2015RS005685S64265550