Circularly Polarized Antenna Ranging Under Rotation and Reflections
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Solution Overview
Problem
Existing distance measurement systems using circularly polarized signals face challenges in accurately determining the distance between antenna units due to reflections from metal surfaces and rotation along the line-of-sight axis, which complicates phase measurements and reduces accuracy.
Innovation Solution
A method involving two-way transmission of signals with opposite circular polarizations between antenna units to determine phase sums, compensating for rotation and reflections, allowing for high-accuracy distance evaluation using simpler and cheaper antenna units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If circularly polarized signals are used to reduce reflection effects, then measurement precision is improved, but rotation along the LOS axis affects phase measurements and deteriorates measurement precision
Solution Approach 1:
The patent transmits signals with different circular polarizations (first and second circular polarizations) to enable differentiation between rotation effects and distance measurements. By changing the polarization parameter and measuring phase differences across multiple polarizations, the system can compensate for rotation along the LOS axis while maintaining high distance measurement accuracy.
2Measurement precision
If joint solution of rotation angle and position coordinates is used to eliminate rotation effects, then measurement precision is improved, but device complexity increases due to requiring large number of satellites
Solution Approach 1:
The patent uses multiple circular polarizations as an additional measurement parameter to directly resolve rotation effects without requiring a joint solution approach. This allows accurate distance measurement with only two antenna units, avoiding the complexity of requiring large numbers of satellites or reference stations.
3Measurement precision
If reference station is used for terrestrial navigation, then measurement precision is improved, but ease of operation deteriorates due to impracticality of reference station deployment
Solution Approach 1:
The patent extracts and eliminates the requirement for reference stations by using two-way signal transmission between only two antenna units. The system achieves accurate distance measurement by having each unit transmit and receive signals, determining phase information locally, and computing distance without external reference infrastructure.
4Ease of operation
If reflected signals are present in transmission, then measurement precision deteriorates due to phase distortion, but ease of operation is improved by not requiring specialized signal processing
Solution Approach 1:
The patent changes the signal polarization parameter to differentiate between direct and reflected signals. By transmitting with different circular polarizations and measuring the resulting phase differences, the system can identify and compensate for reflection effects while maintaining simple receiver design.
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
Enables sub-millimeter accuracy in distance measurements between antenna units by mitigating the effects of reflections and rotation, without requiring expensive high-quality antenna units or additional reference stations.
Implementation Method 1
Circularly polarized signals are known as especially advantageous in being able to reduce the effect of reflected signals from metal surfaces
Implementation Method 2
the phases of one or more transmitted signals that are received by the receiving device may be determined and used in distance measurements
Data Source
AI summary
A method for evaluating a distance between at least a first antenna unit and a second antenna unit by two-way transmission of at least two signals having different circular polarizations between the antenna units. Phase information is determined and used to determine at least a first phase sum and a second phase sum, where the phase sums are further utilized in determination of at least one distance indicator that is indicative of the distance between the first antenna unit and the second antenna unit.