Antenna Time Delay Calibration via Dual-Path Cross-Correlation

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Solution Overview

Problem

Existing antenna systems face challenges in accurately determining time delays introduced by antennas and their associated circuitry, which affects the precision of time-of-flight determination and ranging operations due to manufacturing variations and environmental factors.

Innovation Solution

An apparatus comprising a transceiver, a first antenna connected via antenna circuitry for impedance matching and filtering, and a second antenna bypassing the circuitry, with a calibration device that determines time delays by cross-correlating signals sent and received through both antennas, allowing for calibration and normal-operation modes to account for antenna and circuitry delays.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single antenna is used for both transmission and reception, then the device complexity is reduced, but the time delay measurement precision deteriorates due to inability to separate calibration and operation paths

Engineering Contradiction:
Improveantenna system complexityVSAvoidtime delay measurement precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The antenna system is segmented into a first antenna connected through antenna circuitry for normal operation and a second antenna connected bypassing the circuitry for calibration purposes. This segmentation allows independent calibration of the antenna circuitry time delay without affecting the operational antenna path, thereby resolving the contradiction between device complexity and measurement precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A third antenna is introduced as an intermediary element to facilitate time delay measurement. The third antenna receives signals from both the first and second antennas, enabling the calibration device to compare signal paths and determine the time delay introduced by the antenna circuitry without disrupting the normal operational path between the transceiver and first antenna.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If antenna circuitry is used for impedance matching and filtering, then the signal quality is improved, but the time delay introduced by the circuitry reduces the accuracy of time-of-flight determination

Engineering Contradiction:
Improvesignal qualityVSAvoidtime-of-flight determination accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The second antenna serves as an intermediary reference path that bypasses the antenna circuitry. By comparing the signal received through the first antenna (which passes through the circuitry) with the signal received through the second antenna (which bypasses the circuitry), the calibration device can isolate and measure the time delay introduced by the impedance matching and filtering circuitry, thereby compensating for it in time-of-flight calculations.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the connection parameter of the second antenna to bypass the antenna circuitry, creating a reference path with different electrical characteristics. This parameter change enables the calibration device to measure and compensate for the time delay introduced by the circuitry's impedance matching and filtering functions, maintaining both signal quality and time-of-flight accuracy.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If manufacturing variations and environmental factors are present, then the adaptability of the antenna system is improved, but the consistency of time delay measurements deteriorates

Engineering Contradiction:
Improveenvironmental adaptabilityVSAvoidtime delay measurement consistency
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The calibration device performs time delay measurements using both antenna paths and feeds this measurement information back to the transceiver. The transceiver uses this feedback to compensate for time delay variations caused by manufacturing variations and environmental factors, thereby maintaining consistent time-of-flight measurements despite changes in operating conditions.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary calibration measurements through the second antenna path before normal operation to establish baseline time delay characteristics. This preliminary action allows the system to pre-compensate for manufacturing variations and anticipate environmental effects, maintaining measurement consistency across different operating conditions.

Inventive Principle:
Principle #10Preliminary action

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

This solution enables precise time delay calibration, improving the accuracy of time-of-flight determinations and ranging operations by isolating and accounting for antenna and circuitry delays, thereby enhancing the reliability of distance measurements.

Implementation Method 1

determine a time delay introduced by at least the first antenna and said antenna circuitry based on at least one of: a signal sent by the transceiver from the first antenna and received by the transceiver via the second antenna; and a signal sent by the transceiver from the second antenna and received by the transceiver via the first antenna

Methodology Applied
Scientific EffectTime of flight: Time of Flight

Data Source

PatentEP3435563B1Apparatus and method for determination of a time delay
Publication Date: 2020.06.10 NXP BV
  • EP3435563B1 patent drawingFigure 1~2
  • EP3435563B1 patent drawingFigure 3~4
  • EP3435563B1 patent drawingFigure 5~6

AI summary

An apparatus comprising: a transceiver; a first antenna connected to the transceiver via antenna circuitry to provide for one or more of impedance matching and filtering; a second antenna connected to the transceiver bypassing said antenna circuitry; a calibration device configured to determine a time delay introduced by at least the first antenna and said antenna circuitry based on at least one of: a signal sent by the transceiver from the first antenna and received by the transceiver via the second antenna; and a signal sent by the transceiver from the second antenna and received by the transceiver via the first antenna.