Array Antenna Device Grating Lobe Suppression via Dual-Periodic Element Arrangement
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Solution Overview
Problem
Existing array antenna technologies face challenges in suppressing grating lobes during beam scanning, as the angle at which grating lobes occur changes, making it difficult to suppress all lobes in the desired detection angle range.
Innovation Solution
An array antenna device with two types of antenna element arrangements, each with antenna elements spaced at integral multiples of a minimum interval, where the intervals are set such that the grating lobe does not occur in the detection angle range, and the integers used for spacing are relatively prime, allowing for comparison of detection results to remove erroneous detections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the element-antenna distance is reduced to be sufficiently smaller than the wavelength, then the grating lobe is prevented from appearing in the scanning range, but the antenna design becomes constrained by wavelength and distance limits
Solution Approach 1:
The invention divides the antenna system into two separate arrays: a first array antenna with element intervals of D×K1 and a second array antenna with element intervals of D×K2. Each array independently handles grating lobe suppression for different angular ranges, collectively covering the full scanning range without requiring extremely small element intervals throughout.
Solution Approach 2:
The invention transitions from a single-dimensional element interval parameter to a two-dimensional parameter space by introducing two different interval multiples (K1 and K2). This allows the system to achieve grating lobe suppression across wide angles without constraining the basic element interval D to be much smaller than the wavelength.
2Adaptability or versatility
If beam scanning is performed in an array antenna, then the detection angle range is expanded, but the grating lobe occurrence angle changes making it difficult to suppress all lobes
Solution Approach 1:
The invention makes the system dynamically adaptable to beam scanning by using two array configurations with different interval characteristics. As the beam scans across different angles, the combination of the two arrays ensures that grating lobes are suppressed at all scanning positions, not just at a fixed angle.
Solution Approach 2:
The invention changes the effective element interval parameter dynamically through signal processing that combines results from two arrays with different interval multiples. This allows the system to maintain grating lobe suppression across varying scan angles without physically adjusting the antenna structure.
3Reliability
If two types of antenna element arrangements with different periodicities are used, then grating lobe suppression is improved, but the device complexity increases
Solution Approach 1:
The invention merges two relatively simple array configurations (first array with interval D×K1 and second array with interval D×K2) into a unified system. The combined use of these two arrays achieves superior grating lobe suppression that would be difficult to obtain with a single complex array design.
Data Source
AI summary
An array antenna device includes a plurality of antenna elements arranged to include a first antenna element arrangement in which antenna elements are arranged at element intervals having predetermined periodicity and a second antenna element arrangement in which antenna elements are arranged at element intervals having predetermined periodicity different from the periodicity in the first antenna element arrangement. The array antenna device includes a control unit configured to remove erroneous detection caused by a grating lobe based on a comparison of a detection result by an array antenna of the first antenna element arrangement and a detection result by an array antenna of the second antenna element arrangement.