A s-band sixteen-hole te21 mode coupler

Abstract

The invention belongs to the technical field of self-tracking feeds in radar antenna systems, and in particular relates to an S-band sixteen-hole TE21 mode coupler. The invention comprises a circular waveguide and at least four rectangular secondary waveguides, the length direction of each rectangular secondary waveguide is parallel to the axis of the circular waveguide; the narrow side of the rectangular secondary waveguide is fixedly connected to the outer wall of the circular waveguide, and is arranged along the axial direction of the circular waveguide at the fixed surface The coupling holes in a linear array are connected to the circular waveguide and the corresponding rectangular sub-waveguide; the number of coupling holes at each rectangular sub-waveguide is 16 and the shape is an oblong hole, and the hole spacing S of the coupling holes at each rectangular sub-waveguide is equal to Spacing layout. Each rectangular secondary waveguide of the present invention only needs 16 coupling holes to realize the complete coupling of the current TE21 mode, and at the same time, it can suppress the TE11 mode and other high-order modes by more than 40dB, and the structure is more compact and extremely It meets the development trend and engineering requirements of the miniaturization of the self-tracking feed.

Description

technical field [0001] The invention belongs to the technical field of self-tracking feeds in radar antenna systems, and in particular relates to an S-band sixteen-hole TE21 mode coupler. Background technique [0002] The TE21 mode coupler is a device that couples the TE10 mode in the rectangular secondary waveguide into the TE21 higher order mode in the circular waveguide, and then generates a difference pattern for tracking. TE21 mode has high tracking accuracy and compact coupler structure, so it is used more and more in satellite communication and spaceborne radar. In actual operation, the TE11 communication signal incident from the reflector antenna will pass through the main channel of the TE21 coupler and output in the form of a sum signal with little loss. When the electrical axis of the antenna coincides with the incoming wave direction, there is no error signal output; and when the antenna electric axis deviates from the incoming wave direction, the difference bea...

AI Technical Summary

Problems solved by technology

The defect of the traditional TE21 mode coupler is that since the TE21 mode coupler only couples the TE21 mode and does not couple (or suppress) other modes, it is required that the suppression degree of the main mode TE11 mode be above 40dB, so that the TE21 mode and the TE11 mode In order to work without interfering with each other; at the same time, the coupling adopts a circular hole array layout, and different aperture sizes and coupling hole spacing have a greater impact on the suppression of other modes other than the coupled wave pattern and the coupling bandwidth.

At present, the commonly used coupling function is the constant weighted Bessel distribution, so the number of circular hole-shaped coupling holes is often taken as 48 or 32; for the TE21 mode coupler of the S-band with a lower frequency band, since it is necessary to meet the suppression of other modes above 40dB, so The number of coupling holes is generally 48. At this time, the overall device length reaches more than 2 meters, and the size is huge, which obviously does not meet the development trend and engineering requirements of the miniaturization of the self-tracking feed.

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