Radar Array Antenna Power Distribution via Reflected Standing Waves
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Solution Overview
Problem
Conventional group antennas for radar sensors face challenges in suppressing side lobes and cross-polarization due to transformer disturbances in the feed lines, leading to power losses and increased costs from using absorbers to manage excess power.
Innovation Solution
The solution involves placing circuit elements for power distribution in the feed lines to individual antenna elements, using a strip line capacitively coupled to the feed line, and designing the feed line to reflect excess power back into the antenna elements, eliminating the need for transformers and absorbers, thereby minimizing side lobes and cross-polarization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If transformers are provided in the feed line to distribute power to antenna elements, then power distribution to antenna elements is achieved, but disturbances lead to undesired emissions and reflections, limiting side lobe suppression
Solution Approach 1:
The patent removes transformers from the feed line and extracts their power distribution function by placing circuit elements directly in the feed lines to individual antenna elements. This eliminates the harmful disturbances, emissions, and reflections caused by transformers while maintaining power distribution capability.
Solution Approach 2:
The patent segments the power distribution function by placing separate circuit elements in each feed line to individual antenna elements, rather than using a single transformer in the main feed line. This segmentation allows independent control of power to each element and eliminates the need for transformers that cause harmful emissions.
2Loss of energy
If absorbers are used to destroy excess power on the feed line, then power management is achieved, but additional costs and space are required, and higher power losses occur
Solution Approach 1:
The patent converts the harmful excess power that would normally be lost into a beneficial resource by reflecting it back through the antenna elements. The standing wave pattern ensures that antinodes are located at branching points, causing reflected power to be redistributed to antenna elements and radiated with desired directional characteristics, thereby eliminating the need for absorbers and reducing overall power losses.
Solution Approach 2:
The patent implements a feedback mechanism by designing the feed line to reflect excess power back through the antenna elements. The reflective end and carefully selected distances create a standing wave pattern that feeds reflected power back to the antenna elements, converting what would be waste into useful radiation.
3Power
If transformers are used in the feed line for power distribution, then power transformation is achieved, but cross-polarization suppression becomes more difficult
Solution Approach 1:
The patent removes transformers from the feed line and extracts their power transformation function by placing circuit elements directly in the feed lines to individual antenna elements. This elimination of transformers directly reduces cross-polarization effects while maintaining power distribution capability.
4Loss of energy
If the feed line end is left open for power dissipation, then power management is achieved, but undesired radiation leads to more pronounced side lobes
Solution Approach 1:
The patent converts the potentially harmful radiated power from an open feed line end into a beneficial effect by using a reflective end to create a standing wave pattern. The reflected power is redistributed to antenna elements at positions of maximum field strength (antinodes), causing it to be radiated with the desired directional characteristics rather than creating unwanted side lobes.
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
This approach reduces power losses and costs by effectively redirecting excess power within the antenna elements, enhancing the suppression of side lobes and cross-polarization, while maintaining desired directional characteristics.
Implementation Method 1
the feed line is designed to be reflective at the end opposite the oscillator and the distances between the branches of the feed lines and the distance between the last of these branches and the reflective end of the feed line are selected in such a way that the most reflecting end forms a standing wave when superimposed with the incoming wave
Implementation Method 2
the feed line is designed to be reflective at the end opposite the oscillator and the distances between the branches of the feed lines and the distance between the last of these branches and the reflective end of the feed line are selected in such a way that the most reflecting end forms a standing wave when superimposed with the incoming wave
Implementation Method 3
at least one of the circuit elements for power distribution is formed by a feed line in the form of a strip line, which is only capacitively coupled to the feed line
Data Source
Figure 1~6
AI summary
Array antenna for radar sensors, comprising a supply line (14), a plurality of antenna elements (10) that are connected to the supply line by respective feeders (12) and circuit elements (16, 18, 20) for the power distribution to the antenna elements (10), characterized in that one end (15) of the supply line (14) is reflective and the circuit elements (16, 18, 20) for power distribution are exclusively arranged in the feeders (12).