Active Scanning Antenna Drain Modulation for Efficient Beam Control

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Solution Overview

Problem

Existing active antenna systems suffer from poor electrical efficiency due to inefficiencies in amplitude control and potential damage from mismatch effects, leading to increased energy consumption and premature amplifier degradation.

Innovation Solution

Implementing a voltage modulator at the power stage of each active element in the antenna array to manage amplitude via envelope tracking, coupled with fast drain voltage modulation for phase control, optimizing gain and phase settings based on predefined bias laws.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If attenuators are used to control the amplitude of each active antenna element, then the beam formation is managed, but the electrical efficiency of the active antenna deteriorates

Engineering Contradiction:
Improvebeam formation controlVSAvoidelectrical efficiency
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent introduces a voltage modulator as an intermediary device that controls the amplitude of active antenna elements by modulating the voltage supplied to power amplifiers, rather than using traditional attenuators. This voltage modulator acts as a mediator between the control system and the power amplifiers, enabling efficient amplitude control without the energy losses associated with attenuators. The modulator converts control signals into voltage variations that directly affect the power amplifier output, thereby maintaining electrical efficiency while achieving the desired beam formation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the control parameter from amplitude attenuation to voltage modulation. Instead of controlling the amplitude of active antenna elements by attenuating the signal (which causes energy loss), the system modulates the voltage supplied to the power amplifiers. This parameter change allows for efficient amplitude control because voltage modulation directly affects the power amplifier output without dissipating energy as heat, thus resolving the contradiction between beam formation control and electrical efficiency.

Inventive Principle:
Principle #35Parameter changes

2Power

If active elements are configured to generate maximum power, then the peak power is achieved on all antenna elements, but the yield of active elements collapses

Engineering Contradiction:
Improvepeak powerVSAvoidyield
Core Design Contradiction:
PowerVSProductivity

Solution Approach 1:

The patent implements dynamic control of the voltage supplied to power amplifiers through voltage modulators. Instead of statically configuring active elements to generate maximum power (which causes yield collapse), the system dynamically adjusts the voltage based on the required beam formation and operational conditions. This dynamic adjustment allows the system to achieve peak power when necessary while maintaining optimal yield by reducing voltage when full power is not required, thus resolving the contradiction between peak power and yield.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs feedback mechanisms where the control system monitors the performance of active elements and adjusts the voltage modulation accordingly. This feedback loop ensures that when peak power is required, the voltage is increased to maintain yield, and when peak power is not needed, the voltage is reduced to optimize efficiency. The feedback control prevents the yield collapse that occurs with static maximum power configuration by continuously adapting the power delivery to actual operational needs.

Inventive Principle:
Principle #23Feedback

3Productivity

If energy is used for active elements greater than necessary to compensate for yield loss, then the yield is compensated, but the energy consumption increases

Engineering Contradiction:
ImproveyieldVSAvoidenergy consumption
Core Design Contradiction:
ProductivityVSUse of energy by moving object

Solution Approach 1:

The patent changes the energy delivery parameter from fixed high power to dynamically modulated voltage. By using voltage modulators, the system can precisely control the amount of energy delivered to each active element based on actual requirements. This parameter change eliminates the need to over-supply energy to compensate for yield loss, as the voltage modulation ensures optimal energy delivery matched to the instantaneous needs of each element, thus resolving the contradiction between maintaining yield and reducing energy consumption.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP4020834B1Device for controlling an active antenna with scanning
Publication Date: 2026.04.22 THALES SA
  • EP4020834B1 patent drawingFigure 1~2
  • EP4020834B1 patent drawingFigure 3

AI summary

The invention relates to a device for controlling the efficiency of an active scanning antenna comprising at least two transmission channels Txi, one transmission channel comprising a phase control module (2i), a power stage (3i) at the output of which is disposed a radiating element (Ei) characterized in that it comprises at least: - A voltage modulator (5i) located upstream of the power stage of each of the radiating elements, - A control device (10) emitting a drain voltage PWM control signal configured to manage the gain of a power stage according to a predefined first polarization law (31) and to control the phase applied to the drain of the power stage according to a second polarization law (32).