Circular Polarized Antenna Array Phase Control Null Direction
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Solution Overview
Problem
Array antenna apparatuses with concentrically arranged circularly polarized patch antennas face issues with axis ratio and broadband frequency characteristics, particularly around radiation nulls, leading to deteriorated circular polarization characteristics.
Innovation Solution
The antenna apparatus includes a configuration of at least four circularly polarized antennas arranged in a planar shape with phase adjustment circuitry to set specific phase differences between antennas, ensuring balanced current amplitudes and phases, which improves axial ratio characteristics and allows for adjustable radiation null directions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If patch antennas are concentrically arranged to provide phase difference, then mobile communication with small configuration is enabled, but axis ratio and broadband frequency characteristics are deteriorated
Solution Approach 1:
The patent transitions from a symmetric concentric arrangement to an asymmetric sequential arrangement where antennas are positioned at different distances from the center along a radial direction. This asymmetric positioning, combined with specific phase differences (0°, 90°, 180°, 270°), resolves the contradiction by maintaining compact size while improving circular polarization characteristics and broadband frequency response.
Solution Approach 2:
The patent moves from a two-dimensional concentric circular arrangement to a one-dimensional radial sequential arrangement. This dimensional change allows for optimized phase distribution and current balance across frequencies, thereby improving axis ratio characteristics while maintaining a compact form factor suitable for mobile devices.
2Device complexity
If concentric circular arrangement is used, then simple configuration is achieved, but radiation null causes deteriorated axis ratio around null
Solution Approach 1:
By arranging antennas asymmetrically along a radial line at different distances from the center, the patent eliminates the problematic radiation null characteristics of concentric arrangements. This asymmetric configuration simplifies the overall structure while achieving superior axis ratio performance through optimized current distribution and phase relationships.
3Speed
If phase difference is provided among concentric patch antennas, then directivity control is achieved, but broadband frequency characteristics are deteriorated
Solution Approach 1:
The patent pre-configures specific phase differences (0°, 90°, 180°, 270°) among the sequentially arranged antennas to establish optimal current balance across the operating bandwidth. This preliminary phase configuration ensures both effective directivity control and broad frequency coverage without the deterioration seen in concentric arrangements.
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 configuration enhances axial ratio characteristics around radiation nulls, achieving excellent circular polarization performance and maintaining low axial ratio across a broad frequency band, with the ability to optionally set the null direction.
Implementation Method 1
patch antennas as circularly polarized antennas
Implementation Method 2
circularly polarized antennas are concentrically arranged
Implementation Method 3
phase adjustment circuitry configured to adjust phase relationship between first to Nth signals
Data Source
AI summary
According to one embodiment, an antenna apparatus includes at least four first to Nth circularly polarized antennas in a planar shape; and phase adjustment circuitry adjusting phase relationship between first to Nth signals of the first to Nth circularly polarized antennas. The first to Mth circularly polarized antennas and the M+1th to Nth circularly polarized antennas are arranged at positions surface-symmetrical to each other. The first to Nth circularly polarized antennas are rotated in direction at first to Nth angles with respect to a first direction parallel to the first to Nth circularly polarized antennas. The phase adjustment circuitry is configured to set phases of the first to Mth signals to first to Mth phases corresponding to the first to Mth angles, and set phases of the M+1th to Nth signals to M+1th to Nth phases added by a first value to phases corresponding to the M+1th to Nth angles.