Rotatable Antenna Direction Estimation for Low Frequency Bands
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Solution Overview
Problem
In radio communication systems, especially those using low frequency bands like the VHF band, array antennas with high directivity are cumbersome and difficult to install due to large antenna elements, making it challenging to estimate radio wave arrival directions effectively.
Innovation Solution
A radio wave arrival direction estimation device that uses a rotatable antenna with non-uniform antenna patterns to measure reception intensities at various angles, calculates a matching degree between these angles and patterns, and estimates the arrival direction based on maximum matching degree, eliminating the need for high-directivity array antennas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an array antenna with high directivity is used to estimate radio wave arrival direction, then measurement precision is improved, but device complexity and installation difficulty increase due to large antenna elements in low frequency bands
Solution Approach 1:
The patent employs a rotatable antenna that can dynamically change its orientation angle to sequentially scan different directions. This dynamic approach replaces the static, complex array antenna structure with a simpler single antenna system that achieves high-directivity measurement through temporal scanning rather than spatial arrangement.
Solution Approach 2:
The patent creates a virtual array antenna effect by copying the measurement process across multiple angles. Instead of using multiple physical antenna elements simultaneously, the system sequentially measures reception intensity at different angles and processes these copied measurements to estimate arrival direction, thereby achieving array antenna performance with a single physical antenna.
2Measurement precision
If an array antenna is used in low frequency bands, then arrival direction estimation accuracy is improved, but ease of manufacture and installation deteriorate due to increased antenna element size
Solution Approach 1:
The patent segments the arrival direction estimation process into multiple discrete angular measurements. Instead of requiring a complete array antenna structure to be manufactured and installed as one complex system, the solution divides the measurement into sequential steps at different angles, allowing the use of a single, simpler antenna that can be easily manufactured and installed.
Solution Approach 2:
The patent replaces the mechanical complexity of constructing and installing a large array antenna with a rotatable mechanism. This substitution transforms the problem from one requiring precise spatial arrangement of multiple elements to one requiring only a single antenna with rotational capability, significantly easing manufacturing and installation in low frequency bands.
Data Source
AI summary
A radio wave arrival direction estimation device according to an embodiment includes an antenna angle acquisition unit that acquires each of antenna angles indicating a plurality of different directions in which antennas having non-uniform antenna patterns are sequentially directed, a reception intensity measurement unit that measures reception intensities at which the antenna has received a radio wave at each of the antenna angles acquired by the antenna angle acquisition unit, a matching degree Calculation unit that calculates a matching degree between the antenna angle acquired by the antenna angle acquisition unit and the reception intensity measured by the reception intensity measurement unit, and an antenna pattern of the antenna for each antenna angle acquired by the antenna angle acquisition unit, and an estimation unit that estimates an antenna angle at which the matching degree Calculated by the matching degree Calculation unit is the maximum as an arrival direction of the radio wave.