This paper introduces a metamaterial (MTM)-based resonant structure and applies it to relativistic magnetrons (RMs) with an all-cavity axial extraction technique. The MTM is designed overcome the size limitations of conventional RMs enable π-mode operation below cutoff frequency traditional structures. High-frequency analysis confirms double-negative characteristics structure, enabling frequency. Particle-in-cell simulation CST was employed compare performance RM state-of-the-art design...

This paper reports the investigations of a dielectric filled relativistic magnetron with diffraction output (MDO) on frequency agile. The mechanism agile is theoretically analyzed. Particle-in-cell simulations and preliminary experiments prove analytics. In experiments, under working conditions, 605 kV 0.3 T, microwave 1.98 GHz, 200 MW radiated from an A6 type MDO when 95% Al2O3 ceramics total thickness 0.9 cm are filled. Compared 3.72 240 obtained without filled, S band to L achieved.

The relations between configurations of a relativistic magnetron with diffraction output (MDO) and radiation patterns obtained by experimental investigations are presented in this paper. A fluorescent lamps array is used to snap microwave radiated from an A6 type MDO. Experimental results well agreement computer simulations. Conclusions experiments that (1) when MDO operates at 2π mode, all cavities tapered onto the port, can directly radiate TE01 mode. (2) TEn1 (n > 0, n integer)...

A modified relativistic magnetron (RM) with TEM output mode is proposed. By setting the coupling slots at bottom of resonant cavities in transmission region rather than interaction region, besides possessing original RM's advantages high power conversion efficiency and radiating lowest order mode, RM not only improves compactness miniaturization magnetic field system, which beneficial to realize RMs packed by a permanent magnet, but also robustness operating frequency structural...

A compact mode conversion configuration in A6 relativistic magnetron is proposed, and the operating π-mode can radiate axially with TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> through a rectangular waveguide which designed to match anode. This design, on one hand, makes both diameter axial length of minimized, so that volume coils applied magnetic field distance between electron dump anode block be reduced. On other it provides...

A novel TE11 mode axial output structure for a compact relativistic magnetron (RM) is proposed. This magnetron, operating in the π-mode, can axially radiate microwaves with through cylindrical waveguide which designed to match anode. design, on one hand, minimizes both radial and sizes of so that volume weight magnetic coils itself drifting distance leakage electrons from interaction region be reduced. On other it provides relatively purer radiated as result limit dimension frequency. In...

Relativistic magnetron (RM) is a popular high power microwave device. Filling the resonant cavities with low-loss dielectric well-proven technology that improves performance of RM. In order to enhance efficiency, dielectric-filled relativistic (DFRM) presented and investigated numerically KARAT code in this paper. The simulation results indicate maximum efficiency enhanced from 50.0% conventional RM 56.0% DFRM when applied voltage magnetic field are 280 kV 0.5 T, respectively. Besides,...

A novel relativistic magnetron (RM) with a circularly polarized TE11 coaxial waveguide mode and its corresponding excitation are investigated in this paper. By operating the 4π/5 ten-cavity RM compactly designing structure all cavity-magnetron axial extraction technique, can directly output reversible direction of rotation without any converters. In addition, analysis be generalized to 2N-cavity RM, where 2N > 4 is number cavities. Results 3D particle-in-cell (PIC) simulation show that high...

Relativistic magnetrons (RMs) are one of the most promising high power microwave devices. A high-efficiency relativistic magnetron (HERM) with a novel all-cavity extraction structure is presented and investigated theoretically numerically in this paper. Compared conventional RMs an structure, HERM has three improved features. First, single stair introduced into HERM. Second, angular width bigger than that anode slow-wave structure. Third, port set behind vanes axial direction instead being...

The fundamental mode frequency of a dielectric-filled relativistic magnetron is studied theoretically by the method equivalent circuit, and an exact formula derived. To prove validity theoretical formula, simulation investigation performed. results agree well with relative error does not exceed 3%. comparative verify creditability formula.

A frequency tunable relativistic magnetron (RM) with a wide operation regime is proposed. With the all cavity-magnetron axial extraction technique, RM can output TEM mode operating of 4.3 GHz, which demonstrated as dominating by theoretical analysis, cold simulations and hot respectively, corresponding to power 466 MW conversion efficiency 56.4 %. It also achieve tuning bandwidth 0.96 GHz relative 20.8 %, above 400 40 Further simulation results show that has strong performance robustness...

The physical mechanism of the radiation generation all possible output modes relativistic magnetron (RM) with cavity-magnetron axial extraction technique is theoretically analysed, and necessary conditions for generating these are obtained respectively. Assuming that n 0 number electron spokes, N ≥ 4 as total cavities an even number, k a nonnegative integer, some conclusions can be drawn follows. If = kN true, no mode excited in coaxial waveguide; if (2k + 1)N/4 linearly polarized (4k 2)N/4...

Relativistic magnetron (RM) is a promising high-power microwave source, whose advantages include high efficiency, power, and compact configuration. Enhancing power efficiency output are the most important two development directions for RM. Based on targets, RM presented investigated numerically experimentally in this paper. When diode voltage 485 kV, beam current 6.9 kA, magnetic field 0.34 T, generated with of 1.35 GW, frequency 1.47 GHz, 40.3% experiments.

Field analysis method is used to derive the dispersion relation of rising-sun magnetron with sectorial and rectangular cavities. This then extended general case in which can be multi-group cavities different shapes sizes, from relations conventional magnetron, magnetron-like device obtained directly. The results show that relative errors between theoretical simulation values are less than 3%, cutoff frequencies π mode 2%. In addition, influences each structure parameter on frequency...

A K-band large coaxial relativistic backward wave oscillator has been investigated by the 2.5-D particle-in-cell code. This device can generate high-power microwave at a constant frequency with efficiency increasing radius of electron beam and average slow-wave structure. The simulation results show that power conversion reach 38.8% 25.48 GHz output 1.65 GW, while energy 196 kV carries current 21.6 kA guided magnetic field 2.5 T.

Since its invention in 1921 by Hull, magnetrons have undergone rapid development, transitioning from low-power devices to high-power relativistic (RMs). However, research on RMs has been predominantly confined L-X bands until now. To explore the potential of RM higher frequency and align with trend toward miniaturization microwave sources, a Ku-band investigated this paper. Theoretical analysis dictates selection 24 cavities for optimal performance at low magnetic field. Utilizing...

Relativistic magnetron (RM) with all cavity-magnetron axial extraction (ACMAE) has attracted much attention, benefiting from its good performance. In this paper, RM ACMAE is generalized to a general case called azimuthal-periodic-cavity due the introduction of two structure parameters R and S, where indicates number cavities between in coupling waveguide S adjacent waveguides. The necessary conditions for mode excitation are theoretically investigated verified by simulations. Using...

Contact matrices are an important ingredient in age-structured epidemic models to inform the simulated spread of disease between sub-groups population. These generally derived using resource-intensive diary-based surveys and few exist Global South or tailored vulnerable populations. In particular, no contact for refugee settlements - locations under-served by general. this paper we present a novel, mixed-method approach, deriving populations which combines lightweight, rapidly deployable,...