0000000000482367
AUTHOR
Angel Vegas
Multipactor Effect in a Parallel-Plate Waveguide Partially Filled With Magnetized Ferrite
The aim of this paper is the analysis of the multipactor effect in a parallel-plate waveguide when a ferrite slab, transversally magnetized by a static magnetic field parallel to the waveguide walls, is present. Employing an in-house developed code, numerical simulations are performed to predict the multipactor radio frequency voltage threshold in such a ferrite-loaded waveguide. Variations of the ferrite magnetization field strength and the ferrite slab height are analyzed. Effective electron trajectories are also shown for a better understanding of the breakdown phenomenon, finding different multipactor regimes.
Compressibility Systematics of Calcite-Type Borates: An Experimental and Theoretical Structural Study on ABO(3) (A = Al, Sc, Fe, and In)
The structural properties of calcite-type orthoborates ABO(3) (A = Al, Fe, Sc, and In) have been investigated at high pressures up to 32 GPa. They were studied experimentally using synchrotron powder X-ray diffraction and theoretically by means of ab initio total-energy calculations. We found that the calcite-type structure remains stable up to the highest pressure explored in the four studied compounds. Experimental and calculated static geometries (unit-cell parameters and internal coordinates), bulk moduli, and their pressure derivatives are in good agreement. The compressibility along the c axis is roughly three times that along the a axis. Our data clearly indicate that the compressibi…
Pressure-induced phase transitions in AgClO4
11 pags, 9 figs, 4 tabs. -- PACS number(s): 62.50.−p, 64.70.K−, 61 .50.Ks, 64.30.−t
Novel multipactor studies in RF satellite payloads: Single-carrier digital modulated signals and ferrite materials
In this work it is reviewed the most novel advances in the multipactor RF breakdown risk assessment devoted to RF satellite microwave passive devices employed in space telecommunication systems. On one side, it is studied the effect of transmitting a single-carrier digital modulated signal in the multipactor RF voltage threshold in a coaxial line. On the other hand, an analysis of the multipactor phenomenon in a parallel-plate waveguide containing a magnetized ferrite slab it is presented.
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 3-D 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
Recent advances of the multipactor RF breakdown in RF satellite microwave passive devices
The main goal of this work is the review of the recent advances in the study of the multipactor RF breakdown phenomenon in RF satellite microwave passive devices for space telecommunication applications developed in the Val Space Consortium. In this work several topics related with the multipactor phenomenon will be discussed.