Drone Antenna Beam Measurement Under Multipath Reflection
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Solution Overview
Problem
In environments where radio waves are reflected, such as outdoors, accurately measuring antenna radiation patterns is challenging due to multipath interference, which degrades the efficiency of wireless power transmission to aerial moving bodies like drones.
Innovation Solution
A radio wave measurement system using a drone equipped with a monitor antenna and detector to measure the amplitude and phase of radio waves, combined with a mobile command device for data processing, allows for accurate beam shape measurement by scanning in two or three dimensions, reducing the influence of multipath reflections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If measurement is performed in an anechoic chamber environment, then measurement precision is improved, but device complexity and loss of time increase
Solution Approach 1:
The patent introduces a position measurer as an intermediary device that tracks the three-dimensional position of the aerial moving body. This position information serves as a mediator between the received signal strength and the radiation pattern calculation, enabling accurate measurements without requiring an anechoic chamber environment. The position data compensates for the effects of multipath interference by providing spatial context for signal analysis.
Solution Approach 2:
The patent replaces the mechanical/physical anechoic chamber structure with a computational approach using a radiation pattern calculator. Instead of physically eliminating reflections through absorptive materials, the system uses signal processing and position-based calculations to achieve accurate radiation pattern measurements in ordinary environments.
2Ease of operation
If measurement is performed in outdoor environments, then ease of operation is improved, but measurement precision deteriorates due to multipath interference
Solution Approach 1:
The patent moves the measurement probe from ground level to three-dimensional aerial space using an aerial moving body (drone). This dimensional transition allows the measurement system to operate above ground-based reflectors and multipath sources, enabling outdoor measurements while maintaining precision. The aerial moving body traverses a three-dimensional measurement space around the antenna under test.
Solution Approach 2:
The position measurer and radiation pattern calculator work together as computational intermediaries that process the relationship between spatial position and received signal strength. This computational mediation enables the system to extract accurate radiation pattern information even in the presence of outdoor multipath interference, maintaining measurement precision while improving ease of operation.
3Productivity
If radio wave radiation direction control is inaccurate, then adaptability is improved for general applications, but productivity of wireless power transmission deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where the measured radiation pattern data is used to optimize the wireless power transmission system's beam direction control. The position measurer continuously tracks the aerial moving body's location, and the radiation pattern calculator provides feedback information about the antenna's actual radiation characteristics, enabling precise directional control for efficient power transmission.
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 system enables precise measurement of radio wave beam shapes with reduced multipath interference, improving the accuracy and efficiency of wireless power transmission to aerial moving bodies.
Implementation Method 1
a measurement antenna 14 to receive the radio wave 2
Implementation Method 2
When a radiation pattern of an antenna is measured in an environment where a radio wave is reflected, it is difficult to measure the radiation pattern with high accuracy due to an influence of multipath
Data Source
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AI summary
When a radiation pattern of an antenna is measured in an environment where a radio wave is reflected, it is difficult to measure the radiation pattern with high accuracy due to an influence of multipath. A radio wave measurement system includes: an aerial moving body 3 to move or to hover above a measurement target antenna 30 for radiating a radio wave 2 in a sky direction; and a position measurer 18 to measure a position of the aerial moving body 3. The aerial moving body 3 is mounted with a measurement antenna 14 to receive the radio wave 2 and a radio wave measurer 15 to measure received radio wave data 73 including at least one of an amplitude and a phase of the radio wave 2 received by the measurement antenna 14. The radio wave measurement system further includes a radiated radio wave data generator 21 to generate radiated radio wave data 71 including the received radio wave data 73 and the radio wave source relative position data 78 representing measurement point data 74 that is data of a position of the aerial moving body 3 at a point of time when the received radio wave data 73 is measured, as a relative position with respect to the measurement target antenna 30.