Broadband confocal waveguide HE0n mode excitation device

Abstract

The invention discloses a broadband confocal waveguide HE0n mode excitation device, belonging to the technical field of vacuum electronics. The device comprises an output open confocal waveguide section, a closed confocal waveguide mode transition section, a cutoff transition section and an even open waveguide section. A Y-shaped 3dB power divider is arranged at the junction of the closed confocal waveguide mode transition section and the cutoff transition section. The two-channel output waveguide is bent inwardly by 90 degrees and perpendicular to the input waveguide; and the output port receives two microwave signals of equal amplitude in opposite directions. The device of the invention adopts a doubly-fed structure which is perpendicular to the confocal waveguide mirror surface, and hroguh the two pairs of reflection mirrors of the cutoff transition section, high-efficiency conversion of the confocal waveguide HE0n mode can be realized in the broadband range with the flatness in the band. In the millimeter wave and terahertz band, this can be realized by traditional processing methods; for the low sensitivity structural parameters, the device can be directly applied to the input coupling device of a millimeter wave and terahertz band confocal waveguide convolution amplifier and the cold tests for high frequency system characteristics of the convolution amplifier.

Description

technical field [0001] The invention belongs to the technical field of vacuum electronics, and in particular relates to a confocal waveguide mode excitation device applied to confocal waveguide gyro devices in the millimeter wave and terahertz bands. Background technique [0002] Gyrotron is an important millimeter wave-terahertz radiation source device, which has important applications in controlled nuclear fusion, plasma heating, plasma diagnosis, radar system, communication and electronic countermeasures, industrial processing, etc. The confocal waveguide gyro device adopts a new type of confocal waveguide interaction structure, which has good mode selection characteristics compared with the traditional cylindrical waveguide gyrotron, and effectively solves the problem of too small lateral size and the Due to the low average power capacity, severe electron beam interception and processing difficulties, it has important application prospects in the terahertz frequency band...

AI Technical Summary

Problems solved by technology

Among them, the scheme (1) has the simplest structure, but the bandwidth and coupling efficiency are low. The lowest insertion loss reported in the literature is slightly less than 3dB, and the 3dB bandwidth with a center frequency of 140GHz is about 2GHz; scheme (2) uses two output waveguides of the power splitter Double-fed coupling, symmetrical structure, can suppress some asymmetric modes, Wang Jianxun and others proposed a new type of confocal waveguide broadband input coupling device (patent number: CN201610791802.8), the coupling device adopts double-fed coupling structure, through which The two-way coupling waveguide and the confocal waveguide mirror form an angle of θ, which makes the propagation velocity and group velocity of the microwave propagating in the input waveguide and the confocal waveguide match, effectively solving the problem of narrow bandwidth and low coupling efficiency of the traditional confocal waveguide input structure. 14.08GHz 3dB transmission bandwidth in W band

However, this structure does not mention the design of the 3dB power splitter. Because the device uses an input waveguide inclined to the confocal waveguide, the design of the 3dB power splitter is very difficult and difficult to apply in practice.

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