Shared-Antenna Radar Level Gauging With Waveguide Signal Couplers

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing radar level gauge systems for overfill prevention in storage tanks require multiple antennas and separate systems for reliable operation, which can be cumbersome and less effective at higher frequencies like 60 GHz, where a compact and robust solution for multiple functionally independent radar-based level gauges sharing the same antenna is needed.

Innovation Solution

A radar level gauge system comprising two microwave units with separate transmitter and receiver patches and a signal coupling arrangement using hollow waveguide directional couplers and a signal combiner, allowing for independent operation and high sensitivity, enabling reliable overfill prevention with a single antenna.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple separate radar systems are used for overfill prevention, then reliability is improved, but device complexity increases

Engineering Contradiction:
Improveoverfill prevention reliabilityVSAvoidsystem complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple independent radar measurement channels into a single integrated system that shares one antenna. The signal coupling arrangement merges the transmit signals from multiple microwave units and combines the reflected signals, reducing the number of antennas from multiple to one while maintaining functional independence of each measurement channel for reliable overfill prevention

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single antenna serves multiple functions by radiating transmit signals from different microwave units and receiving reflection signals for multiple measurement channels. The signal coupling arrangement enables this multi-functionality by routing signals between the antenna and multiple microwave units, allowing one antenna to support multiple independent level gauging functions

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Ease of manufacture

If conventional low-frequency radar systems are used, then ease of manufacture is improved, but measurement precision deteriorates

Engineering Contradiction:
Improvesystem manufacturabilityVSAvoidlevel measurement precision
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent changes the operating frequency parameter from conventional low frequencies (26 GHz or less) to high frequencies (at least 60 GHz, such as around 80 GHz). This frequency parameter change enables narrower measurement beams and improved measurement precision while the patent maintains ease of manufacture through its innovative signal coupling arrangement using hollow waveguide directional couplers and signal combiners

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If high-frequency radar signals are used, then measurement precision is improved, but signal loss increases

Engineering Contradiction:
Improvelevel measurement precisionVSAvoidsignal loss
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The patent introduces hollow waveguide directional couplers as intermediary components between the microwave units and the antenna. These couplers efficiently guide high-frequency signals (60 GHz or higher) with minimal loss, enabling the system to maintain improved measurement precision while reducing signal loss through optimized signal coupling and combining mechanisms

Inventive Principle:
Principle #24Intermediary (Mediator)

4Reliability

If multiple antennas are used for independent radar channels, then reliability is improved, but antenna size increases

Engineering Contradiction:
Improvemeasurement reliabilityVSAvoidantenna area
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent merges multiple antenna functions into a single antenna by using a signal coupling arrangement that combines transmit signals from multiple microwave units and routes them through one antenna. This consolidation reduces the total antenna area while maintaining the reliability benefits of multiple independent measurement channels through the shared antenna system

Inventive Principle:
Principle #5Merging (Combining)

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 provides a compact and robust solution for high-frequency radar level gauging, ensuring reliable overfill prevention with improved sensitivity and reduced signal loss, allowing for smaller antenna sizes and reduced interference from tank structures.

Implementation Method 1

a transmitter patch coupled to the microwave transceiver for transmitting a first transmit signal; a receiver patch for receiving a first reflection signal resulting from reflection of the first transmit signal at a surface of the product

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 2

an antenna for radiating the first transmit signal and the second transmit signal towards the surface of the product, and for receiving the first reflection signal and the second reflection signal

Methodology Applied
Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Implementation Method 3

a first hollow waveguide directional coupler having a first waveguide section with a first end coupled to one of the transmitter patch and the receiver patch of the first microwave unit

Methodology Applied
Scientific EffectWaveguide propagation: Waveguide

Data Source

PatentEP4375625A1Radar level gauge system propagating multiple individually generated transmit signals by a common antenna
Publication Date: 2024.05.29 ROSEMOUNT TANK RADAR
  • EP4375625A1 patent drawingFigure 1
  • EP4375625A1 patent drawingFigure 2
  • EP4375625A1 patent drawingFigure 3~4

AI summary

A radar level gauge system comprising a first microwave unit including a transmitter patch for transmitting a first transmit signal, a receiver patch for receiving a first reflection signal, and processing circuitry for determining a first level measurement; a second microwave unit including a transmitter patch for transmitting a second transmit signal, a receiver patch for receiving a second reflection signal, and processing circuitry for determining a second level measurement; an antenna; and a signal coupling arrangement including a first hollow waveguide directional coupler, a second hollow waveguide directional coupler, and a signal combiner.