A High-Power Millimeter-Wave Broadband Mode Converter Based on Continuous Grating Structure

Abstract

The invention discloses a high-power millimeter-wave broadband mode converter based on a continuous grating structure, which belongs to the field of microwave transmission of vacuum components. The mode converter includes a circular waveguide radiator, a matching mirror, a polarization grating mirror and a phase correction system. The TE0,1 mold emitted from the circular waveguide radiator into space has a curved wavefront, which is converted into a quasi-planar electromagnetic wave with a suitable beam size after passing through a parabolic mirror. The continuous variable period grating mirror placed behind the ellipsoidal mirror converts quasi-plane waves with no fixed polarization direction and symmetrical field strength distribution into linearly polarized waves with a single polarization direction and strong field strength distribution in the middle and weak at both ends. Finally, the beam spot size and phase of the obtained linearly polarized wave are adjusted and corrected by the phase correction system to generate a TEM00 mode (Gaussian beam) with a specific beam spot size, and complete the conversion of the circular waveguide TE0,1‑TEM00 mode. The invention has the advantages of wide frequency band, high power capacity, compact structure and the like.

Description

Technical field [0001] The invention belongs to the field of microwave transmission of vacuum components, and specifically relates to a high-power millimeter-wave broadband mode converter based on a continuous grating structure, which is used to transfer TE output from a gyrotron 0,1 Mode conversion to TEM suitable for air propagation 00 mold. Background technique [0002] High-power millimeter waves have a wide range of applications in scientific research fields such as long-distance high-resolution radar, electron cyclotron resonance heating, super jammers, accelerators, fine ceramic sintering, material surface treatment, plasma chemistry, etc. The gyro traveling wave tube has the characteristics of high power and wide frequency band, and is an ideal power source in the millimeter wave and sub millimeter wave frequency band. In order to reduce the working loss of the device and improve the efficiency of standing wave interaction, the high-power cyclotron traveling wave tube usu...

AI Technical Summary

Problems solved by technology

However, whether it is a Vlasov-type quasi-optical mode converter or a Denisov-type quasi-optical mode converter, only a single frequency point can be achieved.

In 2000, V.I.Belovsov of the Russian Institute of Applied Physics and others realized TE by using non-quadratic mirrors, grating mirrors with jumping platforms, and matching mirrors. 01 -TEM 00 Broadband conversion of modes [V.I. Belousovs, A.A. Bogdashov, A.V. Chirkov G.G. Denisov, TE 01 -TEM 00 Quasi-Optical Mode Converter, International Journal of Infrared and Millimeter Waves, 2000,21(2):187-192], due to the presence of jumping platforms, there is discontinuity in the grating mirror, which makes the grating mirror prone to shock under high power conditions. Put on

In addition, the transformation structure also has shortcomings such as low purity of the output mode and bulky volume.

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