Multipactor Threshold Estimation Techniques Based on Circuit Models, Electromagnetic Fields, and Particle Simulators

Abstract

Multipactor has become a keylimiting factor of the final performance of satellite communication systems, due to the increase in power levels and/or operating frequency bands. As a result, the critical components of these systems must meet demanding multipactor specifications which should be considered during the design process. This paper describes the different techniques available to predict the multipactor threshold power for radio frequency (RF) and microwave passive hardware under continuous wave (CW) excitation, from cumbersome particle simulations to fast approximate methods based on circuit models. All these techniques have been described and compared together for the first time, including also a detailed description of the configuration issues of commercial particle simulators required to obtain accurate multipactor threshold predictions. The techniques are applied to both wideband and narrowband application examples. The predictions have been compared with measured thresholds of manufactured samples obtained with a novel multipactor test bed, thus allowing to highlight the advantages and limitations of each technique and particle simulator. From this paper, it will be possible to choose the most suitable procedure (and an appropriate simulator, if needed) to obtain multipactor threshold prediction of passive hardware.

A Genetically Based Algorithm to Improve Execution Speed in Multipactor Simulations in Parallel-Plate Waveguides

“…where g n and α i ( f, d, V 0 ) represents the temporal evolution of the electron population composed by n particles, and the population growth factor rate [16], [40] for a given f × d product and V 0 , respectively. Since P is a subset of S, g p is evaluated in a smaller search space and, therefore, has fewer possible parameter combinations compared to f p : S × R → R.…”

“…A Maxwellian particle source is used, whereas one electron per particle is considered. Moreover, it is worth pointing out that the modified Vaughan's SEY curve (aluminum ECSS [36]) is imported, and a temperature of 3 eV is used for the energy distribution of the secondaries [16]. A 2.5 GHz sinusoidal signal (with a duration of 100 ns) is used to excite the structure.…”

“…Usually, the power threshold can be assessed through experimental verification [13]. Nevertheless, considering that experimental tests are time-consuming and expensive, simulation tools have become increasingly important, especially in the design phase of RF components [14], [15], [16].…”

Development of non-conventional microwave devices based on substrate-integrated technology for advanced applications

“…Recent developments in wireless communication systems have resulted in a significant increase in wireless system complexity. As current coding and modulation schemes are reaching the maximum limit established by the Shannon theorem [66], the need for higher data rates inevitably leads to the development of more complex and sophisticated communications systems. Therefore, filters should not only fulfil traditional requirements such as low loss, high isolation, extremely linear phase response, and low cost, but they must also comply with new requirements, including compactness, lightness, integration and frequency agility [67].…”

“…For filters with a homogeneous multi- pactor gap, such as those under consideration, the TASE is directly proportional to the voltage, so identifying the critical frequencies and resonators can be accomplished by identifying the highest TASE values. We used the methodology developed in [66,133] to compute the TASE distribution of both filter realisations. The procedure involves extracting the coupling matrix from the measured filter response, which was accomplished using the filter designer module of CST.…”