Vircator Technologies Comparison and Novel Anode Analysis

Valletti, Lorenzo; Fantauzzi, Stefano; Bartocc, Marco; Bia, Pietro; Manna, A. La; Livreri, Patrizia; Paolo, Franco Di; Limiti, Ernesto

doi:10.1109/piers53385.2021.9694817

Cited by 9 publications

(8 citation statements)

References 6 publications

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“…The instantaneous distribution of the particles is shown in Fig. 2; the accumulation of quasi-static charges in the center of the DT (blue zone) shows the presence of a virtual cathode [22]. The signal power in the time domain on the RF output port is shown in Fig.…”

Section: Coaxial Vircator Designmentioning

confidence: 99%

“…In the designed structure, the anode is a section of DT semi-permeable to electrons, with a sheet transparency of 80% [22], [24], [25], while the emitter is a section of the cathode cylinder; R a is the radius of the DT and the anode, and R c is the radius of the cathode and the emitter. The external cavity guarantees the vacuum and the matching.…”

Section: Coaxial Vircator Designmentioning

confidence: 99%

“…There are many types of vircators [22] and different geometries; the most compact and performing vircator we have studied is the coaxial vircator. Its radial symmetry allows it to obtain a higher power with the same space as the other vircators.…”

Section: Introductionmentioning

confidence: 99%

“…Its radial symmetry allows it to obtain a higher power with the same space as the other vircators. The coaxial vircator usually works with the TM 01 mode, mainly excited by its inherent symmetry; the performances obtained on a coaxial vircator optimized for the TM 01 mode are shown in [22]. However, by modifying the geometry of the coaxial vircator, it is possible to obtain other modes than the TM 01 .…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Innovative Mode Enhancement for High Power Coaxial Vircators

Valletti

Fantauzzi

Paolo

2023

IEEE Trans. Electron Devices

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The size and weight of a high power microwave (HPM) source can make a difference in strategic use. The compactness of the virtual cathode oscillator (vircator) is undoubtedly the most significant advantage of this device. Civil industry and agriculture can use it to treat objects, food, and soils for disinfestation and disinfection. Vircators could also generate electromagnetic pulses (EMPs) to force the arrest of vehicles and drones; EMPs could inhibit or activate improvised explosive devices (IEDs). The coaxial type vircator is a highly compact device. Due to its symmetric geometry, coaxial vircator is typically designed to work with a TM 01 mode. Still, when radiated into space, this mode gives maximum RF energy away from the antenna axis, a situation not desired. Instead, the TE 11 is convenient in applications involving precise antenna pointing since this mode gives a maximum RF energy precisely aligned to the antenna axis. By studying Mathieu functions applied to elliptical waveguides, we improve the performances of a TE 11 mode coaxial vircator using an elliptic drift tube (EDT). This is a completely innovative solution to reduce the mode competition inside the coaxial vircator. The rms and peak output power efficiency of the EDT coaxial vircator were measured on the TE 11 mode, obtaining the values of 6.1% and 10%, respectively, with a peak power of 450 MW in a highly compact device.

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Section: Coaxial Vircator Designmentioning

confidence: 99%

Section: Coaxial Vircator Designmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Innovative Mode Enhancement for High Power Coaxial Vircators

Valletti

Fantauzzi

Paolo

2023

IEEE Trans. Electron Devices

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“…Reaching high powers in small volumes with high fault tolerances, Spatial Power Amplifiers (SPA) are the perfect candidates to replace high power Vacuum Tubes (VT) [1][2][3][4][5][6][7][8][9][10][11][12], especially in space environments. The only field in which vacuum tube technology remains unmatched is in the production of very high pulsed power [13]. Among all the disadvantages of Vacuum Tubes technology, including high bias voltages and heavy weight, the single point failure is the most critical one, especially in the case of space applications.…”

Section: Introductionmentioning

confidence: 99%

High Power Density Spatial Combiner for the Q-Band, Ready for Space Applications

Fantauzzi¹,

Valletti²,

Paolo³

2022

PIER M

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This paper outlines the design characterization and electromagnetic performance of a millimeter-wave high power combining structure, which exploits the spatial power combination technique. The input matching is always below 10 dB over the entire Q band, and the overall weight of the structure is about 500 g. Multiphysics simulations show how this structure is suitable for the most challenging space missions that will arise in next few years. In fact, 100 W of RF power above the frequency of 40 GHz can be delivered while all the specifications for satellite payloads are complied. Other Spatial Power Combiner structures, such as Radial ones, cannot be implemented in space missions since they are much less compact and much heavier than the one presented in this article, and this is the major advantage of this configuration which was specially designed for a space project.

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An Innovative Lens Type FinLine to Microstrip Transition

Valletti

Fantauzzi

Paolo

2022

J Infrared Milli Terahz Waves

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Due to the disadvantages of vacuum tubes in terms of warm-up time, size, and high-voltage needs, solid-state power amplifiers (SSPAs) with gallium nitride (GaN) monolithic microwave integrated circuits (MMICs) are the key solution for power levels up to some kilowatts in continuous wave. An SSPA is the most convenient solution for these RF power levels due to its low weight, small size, negligible warm-up time, low-voltage operation, and high reliability. Spatial power amplifiers (SPAs) combining techniques are the best candidates for SSPAs due to the intrinsic low attenuation in dividing and combining functions. SPAs mainly use two types of probes: transverse and longitudinal, such as FinLines. This paper describes a broadband FinLine to microstrip (FLuS) transition based on dielectric lens theory. Comparative simulations with traditional FinLine transitions show a significant improvement in matching performances and a very significant increase in mechanical resistance of the transition. The proposed innovative FLuS uses a substrate shaping designed according to dielectric lens theory. Frequency simulations of a FLuS inside the WR22 waveguide are shown. These evidence the better performances of this transition than the classic FLuS transition using quarter-wave transformer (QWT) matching. A Q band spatial power combiner with dielectric lens FLuS was made and measured, showing the excellent performances of this innovative FLuS transition.

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Vircator Technologies Comparison and Novel Anode Analysis

Cited by 9 publications

References 6 publications

Innovative Mode Enhancement for High Power Coaxial Vircators

Innovative Mode Enhancement for High Power Coaxial Vircators

High Power Density Spatial Combiner for the Q-Band, Ready for Space Applications

An Innovative Lens Type FinLine to Microstrip Transition

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