Variable Impedance Signal Divider for Adaptive Antenna Arrays

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Solution Overview

Problem

Existing adaptive antenna array systems face energy inefficiency due to the use of absorptive switches, which waste RF power as heat, and struggle with flexible beam reconfiguration while maintaining performance.

Innovation Solution

A feeder device with variable impedance signal dividers that control the reflection and transmission of RF signals, allowing for constructive and destructive interference to direct signals efficiently to antenna elements, eliminating the need for absorptive switches and enabling flexible beam configuration with reduced energy loss.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If absorptive switches are used to switch off antenna elements, then beam reconfiguration flexibility is improved, but energy efficiency deteriorates due to power dissipation as heat

Engineering Contradiction:
Improvebeam reconfiguration flexibilityVSAvoidpower dissipation
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

Instead of absorbing RF power to switch off antenna elements, the patent uses reflective switches that reflect the RF power back through the feeder network to other antenna elements. This inverts the conventional approach by converting power loss into useful signal redistribution, thereby maintaining energy efficiency while achieving beam reconfiguration flexibility.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent converts what would traditionally be harmful reflected power (which causes instability in power amplifiers) into a beneficial resource by directing it through the feeder network to other antenna elements. The reflection is no longer waste but a mechanism for power redistribution and beam forming.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Area of stationary object

If antenna elements are switched off to extend angular coverage, then coverage area is improved, but power along the main beam deteriorates

Engineering Contradiction:
Improveangular coverageVSAvoidmain beam power
Core Design Contradiction:
Area of stationary objectVSPower

Solution Approach 1:

The patent maintains continuous useful action by ensuring that RF power is never absorbed or lost, but continuously redirected to active antenna elements. Even when some elements are switched off for coverage extension, the power is reflected and continuously supplied to the remaining active elements, maintaining main beam power while achieving wider coverage.

Inventive Principle:
Principle #20Continuity of useful action

3Loss of energy

If reflected signals are allowed in the feeder network, then absorptive switches can be eliminated, but signal reflections deteriorate system performance

Engineering Contradiction:
Improveenergy efficiencyVSAvoidsystem stability
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent introduces the feeder network itself as an intermediary that actively manages and directs reflected signals. Instead of allowing uncontrolled reflections that could cause instability, the feeder network with its variable impedance structures guides the reflected power to specific antenna elements, converting a potential harm into a controlled and useful signal distribution mechanism.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 provides a controllable, low-loss method for transmitting or reflecting RF signals, allowing for precise amplitude control and flexible beam patterns, enhancing energy efficiency and reducing heat dissipation in adaptive antenna arrays.

Implementation Method 1

said divided signals are at least one of reflected to said output port and transmitted to said further output port, said degree of reflection and transmission depending on a value of said variable impedance

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

said phase shifts being such that said divided signals received at said output port and said further output port constructively interfere and signals received at outer ports of said signal divider other than said output ports are out of phase and destructively interfere

Methodology Applied
Scientific EffectInterference: Interference

Data Source

PatentEP3128612B1An adaptive antenna array and an apparatus and method for feeding signals to an adaptive antenna array
Publication Date: 2020.11.18 ALCATEL LUCENT SA
  • EP3128612B1 patent drawingFigure 1
  • EP3128612B1 patent drawingFigure 2
  • EP3128612B1 patent drawingFigure 3

AI summary

A feeder device for supplying a radio frequency signal to an adaptive antenna array and the adaptive antenna array are disclosed. The feeder network comprises at least one signal divider. The signal divider comprises: an input port for receiving the radio frequency signal, an output port, a further output port and a variable impedance. The signal divider is configured to divide the input signal and direct the divided signal towards the variable impedance. The divided signals are at least one of reflected to the output port and transmitted to the further output port, the degree of reflection and transmission depending on a value of the variable impedance. The signal divider is configured such that phase shifts are introduced to signals travelling between ports, the phase shifts being such that the divided signals received at the output port and the further output port constructively interfere and signals received at outer ports of the signal divider other than the output ports are out of phase and destructively interfere. The output and the further output ports of the at least one signal divider are configured to supply signals to respective antenna elements of the antenna array.