Magnetically Tuned Attenuator for Low-Noise Gain Compensation

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Solution Overview

Problem

Existing attenuators in radar transceivers degrade uncorrelated noise when used for gain compensation, leading to a decrease in signal-to-noise ratio, and require additional hardware resources.

Innovation Solution

A tunable attenuator is designed with transformer windings and conductive loops underneath, controlled by a MOS switch and voltage control circuit, which allows for adjustable attenuation without significantly increasing hardware resources and minimizing noise degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If conventional attenuators are used for gain compensation, then temperature compensation is achieved, but uncorrelated noise is degraded and signal-to-noise ratio decreases

Engineering Contradiction:
Improvetemperature compensationVSAvoiduncorrelated noise degradation
Core Design Contradiction:
TemperatureVSObject-affected harmful factors

Solution Approach 1:

The patent replaces conventional resistive attenuators with a transformer-based magnetic coupling system. The attenuator uses magnetic field coupling between primary and secondary windings instead of resistive elements, fundamentally changing the attenuation mechanism from electrical resistance to magnetic induction. This substitution eliminates the noise degradation inherent in resistive attenuation while maintaining temperature compensation capability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operating parameters of the transformer by varying the coupling coefficient between windings through adjustable magnetic core positioning or winding configuration. By modifying the magnetic coupling parameter, the attenuation level is tuned without introducing resistive losses, thus maintaining signal-to-noise ratio while achieving temperature compensation.

Inventive Principle:
Principle #35Parameter changes

2Stability of the object's composition

If conventional attenuators are used for gain compensation, then temperature stability is achieved, but additional hardware resources are required

Engineering Contradiction:
Improvegain stabilityVSAvoidhardware resources
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The transformer structure serves multiple functions simultaneously: it provides impedance transformation, signal coupling, and temperature compensation through its magnetic coupling mechanism. The same magnetic core and windings that enable signal transmission also provide the attenuation and temperature stability, eliminating the need for separate compensation hardware.

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

Solution Approach 2:

The patent merges the attenuator function with the existing transformer structure in the radar transceiver. The magnetic coupling elements are integrated into the existing RF signal path, combining the attenuation function with the impedance matching and signal transformation functions already present in the system, thereby reducing overall hardware complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Object-affected harmful factors

If transformer windings with conductive loops are used, then tunable attenuation is achieved with minimal noise impact, but control circuit complexity increases

Engineering Contradiction:
Improvenoise impactVSAvoidcontrol circuit complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The magnetic coupling system provides self-adjusting attenuation characteristics based on temperature variations. The conductive loops and magnetic core automatically adjust the coupling coefficient in response to temperature changes, reducing the need for complex external control circuits while maintaining low noise performance.

Inventive Principle:
Principle #25Self-service

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 provides tunable attenuation with reduced impact on uncorrelated noise and maintains reliable operation across temperature variations without adding extra hardware, ensuring stable signal quality and compact design.

Implementation Method 1

one or more transformer windings configured to facilitate attenuating a signal

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

one or more conductive loops provided underneath the transforming windings; a controller configured to control an amount of current flowing through the conductive loops

Methodology Applied
Scientific EffectElectromagnetic field interaction: Electromagnetic Induction

Data Source

PatentEP4322405A1Tunable attenuator
Publication Date: 2024.02.14 NXP BV
  • EP4322405A1 patent drawingFigure 1A
  • EP4322405A1 patent drawingFigure 1B
  • EP4322405A1 patent drawingFigure 2A

AI summary

In accordance with a first aspect of the present disclosure, a tunable attenuator is provided, comprising: one or more transformer windings configured to facilitate attenuating a signal; one or more conductive loops provided underneath the transforming windings; a controller configured to control an amount of current flowing through the conductive loops, thereby providing a tunable attenuation of said signal. In accordance with a second aspect of the present disclosure, a corresponding method of producing a tunable attenuator is conceived.