Radar Device Multi-Frequency Signal Processing for Distance Resolution

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Solution Overview

Problem

Existing radar devices face difficulties in discriminating closely existing objects and have reduced distance resolution due to the limitations of single-peak waveform signals, which result in inefficient frequency band usage and widened pulse widths.

Innovation Solution

The radar device employs a configuration that includes transmitting and receiving signals of different frequencies, performing quadrature demodulation, and rotating the signals based on predetermined phase information to highlight or suppress specific objects, using multi-peak type transmission signals like Sinc function waveforms to improve distance resolution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a single-peak Gaussian function type waveform signal is used for pulse transmission, then the signal has a well-defined central frequency, but the usable frequency band is not effectively used, causing pulse width to widen and distance resolution to reduce

Engineering Contradiction:
Improvedistance resolutionVSAvoidusable frequency band
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent segments the frequency band by transmitting multiple pulse signals with different central frequencies (first frequency and second frequency). This segmentation allows effective utilization of a broader frequency band while maintaining controlled pulse characteristics, thereby improving distance resolution without wasting frequency resources

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the frequency parameter by transmitting pulses at different central frequencies. This parameter variation enables the system to utilize a wider frequency band effectively, narrowing the pulse width on the time axis and improving distance resolution while avoiding the limitations of single-frequency transmission

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If a single frequency pulse signal is transmitted, then the system is simple to operate, but closely existing objects cannot be discriminated and distance resolution is reduced

Engineering Contradiction:
Improveobject discrimination capabilityVSAvoidsignal transmission complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent adds a frequency dimension to the pulse transmission by using multiple central frequencies. This dimensional expansion enables discrimination of closely existing objects through frequency differentiation, while the processing remains manageable by comparing signals at different frequencies rather than requiring complex spatial or temporal processing

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Measurement precision

If multiple frequencies are used to improve object discrimination, then distance resolution improves, but the processing complexity increases

Engineering Contradiction:
Improvedistance resolutionVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent performs preliminary phase rotation on the received signals before comparison. By pre-rotating the phase of signals at different frequencies to align them, the system simplifies the subsequent processing needed to extract distance information, reducing the overall processing complexity while maintaining improved distance resolution through multi-frequency transmission

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3693758B1Radar device and object detecting method for radar device
Publication Date: 2023.03.01 FURUKAWA ELECTRIC CO LTD
  • EP3693758B1 patent drawingFigure 1
  • EP3693758B1 patent drawingFigure 2~3
  • EP3693758B1 patent drawingFigure 4(A)~4(B)

AI summary

To discriminate closely located objects. The present invention comprises: a transmission means (transmission antenna 16) for transmitting a first transmission signal and a second transmission signal having different frequencies; a reception means (reception antenna 17) for receiving, as a first reception signal and a second reception signal, the first transmission signal and the second transmission signal reflected by one or more objects; a quadrature modulation means (quadrature modulation unit 21) for performing quadrature modulation on the first reception signal and the second reception signal; a rotation means (signal processing unit 22) for rotating, on an IQ plane, at least one of the first reception signal and the second reception signal according to a predetermined phase angle corresponding to a predetermined distance and a first frequency or a second frequency; a processing means for adding or subtracting the first reception signal and the second reception signal one of which has been rotated; and a detection means (data processing unit 23) for detecting the one or more objects on the basis of the processing result by the processing means.