Antenna Device Null Filling via Central Element Voltage Adjustment
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Solution Overview
Problem
Conventional antenna devices are ineffective in filling nulls beyond the first null, limiting their usable range and making them unsuitable for wide angular detection in vehicle collision avoidance radars.
Innovation Solution
The antenna device employs an array of radiating elements with a feeder circuit that adjusts the excitation voltage of central elements to increase the gain in null-filled regions, effectively enhancing the radiation pattern to include second and successive nulls, thereby widening the radar's detection range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If power is fed to upper and lower radiating element groups with unequal division ratio to increase first null gain, then first null filling is improved, but second and successive nulls remain unfilled
Solution Approach 1:
The radiating elements are divided into multiple groups (upper group and lower group) with different excitation characteristics. By segmenting the array and applying different excitation voltages to each group, the patent achieves independent control over different null regions, enabling both first and second null filling simultaneously
Solution Approach 2:
Different excitation voltages are applied to different groups of radiating elements to create local variations in the radiation pattern. The upper and lower groups have different excitation characteristics tailored to fill specific nulls at different angles, achieving localized gain enhancement where needed
2Measurement precision
If conventional antenna device with four radiating elements is used, then first null filling is achieved, but detection range is limited to ±24 degrees
Solution Approach 1:
The patent extends the conventional four-element array by adding more radiating elements to create a larger array structure. This dimensional expansion allows the antenna to cover a wider angular range (±70 degrees or wider) while maintaining null filling capabilities through coordinated excitation of all elements
Data Source
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AI summary
An antenna device includes an array antenna 2 formed of five radiating elements 21 to 25 arrayed on a dielectric substrate 1, and a feeder circuit 3 that feeds a high frequency signal to the radiating elements 21 to 25 making up the array antenna 2. The five radiating elements 21 to 25 are arrayed on a first straight line L1 drawn in a direction horizontal to the ground, and an excitation voltage of the radiating element 23 positioned at the center of the array is set to be 2.2 times or more an average value of excitation voltages of the other radiating elements 21, 22, 24, and 25.