Phased Array Antenna Grating Lobe Suppression via Variable Element Spacing
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Solution Overview
Problem
Phased array satellite communication antennas on moving objects face issues with grating lobes, leading to electromagnetic interference and reduced gain due to the need for a widely-spaced arrangement of antenna elements, which increases power consumption and cost.
Innovation Solution
A planar antenna device with an attitude controller and a scan controller that adjusts the antenna's mechanical attitude and excitation phases to limit beam scanning within a range where grating lobes do not occur, preventing interference and maintaining high gain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the number of antenna elements is reduced, then cost and power consumption are reduced, but the antenna elements must be widely-spaced which causes grating lobe occurrence and gain reduction
Solution Approach 1:
The patent applies dynamics by making the antenna element spacing variable rather than fixed. The antenna elements are arranged with different spacings in different regions of the array, allowing the system to adapt the spacing configuration dynamically to prevent grating lobes while using fewer elements. This non-uniform spacing configuration enables the reduced number of elements to maintain high gain by strategically positioning elements to avoid grating lobe formation in the visible region.
Solution Approach 2:
The patent applies local quality by creating different spacing characteristics in different regions of the antenna array. Specifically, the antenna elements are arranged with first spacing in a first region and second spacing different from the first spacing in a second region. This local variation in spacing allows each region to be optimized for its specific function while collectively preventing grating lobe occurrence across the entire array, thereby maintaining high gain with fewer elements.
2Ease of manufacture
If antenna elements are widely-spaced to reduce the number of elements, then cost is reduced, but electromagnetic interference occurs due to grating lobe transmission/reception
Solution Approach 1:
The patent uses dynamic spacing variation to prevent grating lobe formation that causes electromagnetic interference. By configuring different spacings in different regions, the antenna array eliminates the conditions that would allow grating lobes to form and radiate electromagnetic interference, while still maintaining a reduced total number of elements for lower cost.
Solution Approach 2:
The patent applies local quality by creating region-specific spacing patterns that prevent electromagnetic interference locally while contributing to overall system performance. The first region and second region have different spacing configurations that collectively eliminate grating lobe formation, thereby preventing electromagnetic interference without requiring a full complement of tightly-spaced elements.
3Use of energy by moving object
If the number of antenna elements is reduced, then power consumption is reduced, but beam scanning range is limited by grating lobe constraints
Solution Approach 1:
The patent applies dynamics by using variable spacing configurations that enable broader beam scanning ranges despite having fewer elements. The non-uniform spacing allows the antenna to scan over wider angular ranges without generating grating lobes, thereby maintaining adaptability and versatility in beam steering capabilities while reducing power consumption through element reduction.
Solution Approach 2:
The patent uses local quality by creating different spacing patterns in different regions to expand the overall beam scanning range. The first region and second region with different spacings work together to enable the antenna to scan across wider angles without grating lobe interference, thus improving adaptability and versatility while maintaining lower power consumption.
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 solution enables beam scanning while suppressing the number of antenna elements, preventing grating lobe occurrence and reducing power consumption and cost, while maintaining high gain and minimizing electromagnetic interference.
Implementation Method 1
a planar antenna including a plurality of antenna elements and transmitting and receiving a radio wave to and from a target
Implementation Method 2
adjusts excitation phases of the plurality of antenna elements in accordance with a signal level of a reception signal generated from a radio wave received from the target during performance of the beam scanning, thereby directing a beam from the planar antenna toward the target
Data Source
AI summary
A planar antenna includes a plurality of antenna elements and transmits and receives a radio wave to and from a target. An attitude controller is attached to the planar antenna and controls an attitude of the planar antenna mechanically. An antenna controller controls the attitude controller such that the planar antenna points in a predetermined direction with respect to the target. A scan controller controls beam scanning performed by the planar antenna and adjusts an excitation phase of each of the antenna elements in accordance with a signal level of a reception signal generated from a radio wave received from the target during performance of the beam scanning, thereby directing a beam from the planar antenna toward the target. The scan controller limits a range of the beam scanning to a range within which no grating lobe occurs.