Sinusoidal Folded Waveguide With Slots for Antenna Lobe Suppression
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Solution Overview
Problem
Existing waveguides fail to prevent grating lobes on either side of a horizontal-polarity main beam and X-band lobes on either side of a vertical-polarity main beam in antenna patterns.
Innovation Solution
A folded waveguide with a hollow core and sinusoidal shape, featuring radiation slots that are either parallel or perpendicular to the longitudinal axis, to prevent grating and X-band lobes by allowing controlled electromagnetic radiation leakage through slots, thereby producing specific antenna patterns.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a waveguide is used to improve antenna characteristics, then antenna gain and pattern control are improved, but grating lobes and X-band lobes cannot be prevented
Solution Approach 1:
The waveguide is segmented into multiple surfaces with radiation slots distributed across them. The slots are divided into two groups: longitudinal slots (parallel to the longitudinal axis) and lateral slots (perpendicular to the longitudinal axis), each group addressing different lobe types through spatial segmentation of the radiation aperture.
Solution Approach 2:
Different regions of the waveguide surface are assigned different slot orientations and densities. The longitudinal slots are positioned to suppress vertical-polarity lobes, while lateral slots are positioned to suppress horizontal-polarity lobes. This local differentiation of slot characteristics creates direction-dependent radiation control.
2Object-generated harmful factors
If radiation slots are added to the waveguide, then lobe suppression is achieved, but device complexity increases
Solution Approach 1:
Multiple functions are merged into a single waveguide structure: electromagnetic wave guidance, radiation control, and lobe suppression are all achieved through the integrated folded waveguide with slots. The sinusoidal folding pattern itself serves both as a structural feature and as a means to control the phase and amplitude distribution across the radiation aperture.
Solution Approach 2:
The folded waveguide structure serves multiple purposes simultaneously: it guides electromagnetic waves from the feed, creates the desired radiation pattern through its geometric configuration, and suppresses unwanted lobes through the strategic placement of radiation slots. The same structure that defines the hollow core also defines the slot positions and orientations.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The folded waveguide effectively prevents grating and X-band lobes, enabling precise control over antenna patterns, including horizontal, vertical, and circular polarization, enhancing antenna performance.
Implementation Method 1
The waveguide can include perforations that improve an antenna pattern by leaking some of the electromagnetic radiation that is directed towards the antenna
Data Source
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AI summary
This document describes a folded waveguide for antenna. The folded waveguide may be an air waveguide and includes a hollow core that forms a rectangular opening in a longitudinal direction at one end, a closed wall at an opposite end, and a sinusoidal shape that folds back and forth about a longitudinal axis that runs in the longitudinal direction through the hollow core. The hollow core forms a plurality of radiation slots, each including a hole through one of multiple surfaces that defines the hollow core. The radiation slots are arranged on the one surface to produce a particular antenna pattern. The radiation slots and sinusoidal shape enable the folded waveguide to prevent grating lobes from appearing in the particular antenna pattern on either side of a horizontal-polarity, main beam, or to prevent X-band lobes from appearing in the particular antenna pattern on either side of a vertical-polarity, main beam.