Phased Array Carrier Leak Correction via Pre-calculated DC Offsets

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Solution Overview

Problem

Conventional carrier leak correction methods fail to adequately address fluctuations in carrier leaks due to beam directionality switching in phased array transmission devices, leading to deteriorated reception signal detection accuracy.

Innovation Solution

A phased array transmission device with phase shift units, DC offset correction units, and a correction control unit that calculates and applies correction values to minimize carrier leak components for varying phase rotation amounts, effectively suppressing carrier leak fluctuations by adjusting DC offsets at both the phase shift unit and mixer stages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If conventional carrier leak correction methods are used, then the correction process is simple, but carrier leak fluctuations occur due to beam directionality switching leading to deteriorated detection accuracy

Engineering Contradiction:
Improvedetection accuracyVSAvoidcorrection process complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The correction control unit pre-calculates and stores multiple correction values corresponding to different phase rotation amounts before actual transmission. When beam directionality switches, the appropriate pre-calculated correction value is selected and applied, eliminating the need for real-time recalculation and preventing carrier leak fluctuations.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system measures the actual carrier leak component in the output signal of the mixer, feeds this information back to the correction control unit, which then selects and applies the appropriate correction value from stored candidates. This closed-loop feedback mechanism ensures accurate compensation for carrier leaks across different beam directions.

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If beam directionality switching is performed, then coverage area and adaptability are improved, but carrier leak fluctuations occur deteriorating reception signal quality

Engineering Contradiction:
Improvebeam directionality controlVSAvoidcarrier leak stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The system dynamically adapts the DC offset correction value based on the current beam direction (phase rotation amount). The correction control unit selects from multiple pre-calculated correction values corresponding to different phase rotation amounts, enabling the system to maintain stable carrier leak correction across dynamically changing beam directions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the correction parameter (DC offset correction value) according to the phase rotation amount. By storing multiple correction values corresponding to different phase rotation amounts and selecting the appropriate one based on current beam direction, the system maintains reliable carrier leak correction while enabling flexible beam steering.

Inventive Principle:
Principle #35Parameter changes

3Object-generated harmful factors

If DC offset correction is applied at phase shift unit output, then carrier leak can be corrected, but correction must be recalculated for each phase rotation amount

Engineering Contradiction:
Improvecarrier leak componentVSAvoidcorrection calculation time
Core Design Contradiction:
Object-generated harmful factorsVSLoss of time

Solution Approach 1:

The correction control unit pre-calculates correction values for all expected phase rotation amounts during system initialization or calibration phase and stores them in memory. During actual operation, the appropriate pre-calculated correction value is simply selected based on current phase rotation amount, eliminating the need for time-consuming real-time recalculation.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system transitions from static single-value correction to dynamic multi-value correction. By storing multiple correction values corresponding to different phase rotation amounts and dynamically selecting the appropriate one based on current beam direction, the system achieves both effective carrier leak suppression and fast adaptation without recalculation overhead.

Inventive Principle:
Principle #15Dynamics

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 solution ensures stable carrier leak correction even during beam directionality changes, maintaining detection accuracy and reducing the impact of carrier leak fluctuations on reception signals.

Implementation Method 1

a phase shift unit that applies a phase rotation to a baseband signal

Methodology Applied
Scientific EffectPhase rotation: Phase Modulation

Implementation Method 2

a mixer that subjects an output signal of the first DC offset correction unit to a frequency conversion to a high frequency band

Methodology Applied
Scientific EffectFrequency conversion: Heterodyne

Data Source

PatentEP3226350B1Phased array transmission device and carrier leak correction method
Publication Date: 2020.09.16 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3226350B1 patent drawingFigure 1
  • EP3226350B1 patent drawingFigure 2
  • EP3226350B1 patent drawingFigure 3

AI summary

Provided is a phased array transmission device including: a plurality of transmission branches, each being provided with a phase shift unit that applies a phase rotation to a baseband signal, a DC offset correction unit that adds a first correction value to an output signal of the phase shift unit, and a mixer that subjects an output signal of the DC offset correction unit to a frequency conversion to a high frequency band; and a correction control unit that calculates a second correction value with which a carrier leak component included in an output signal of the mixer is minimized, for each of a plurality of candidates for a phase rotation amount that is set for the phase rotation, and determines the first correction value on the basis of the second correction value.