Variable Gain Amplifier Feedback for Stable RF Output Power

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current wireless communication devices for millimeter wave radar face challenges in cost due to expensive power adjustment techniques, particularly in meeting the minimum output electric power requirements stipulated by radio laws, and struggle to adapt to environmental changes without increasing manufacturing costs.

Innovation Solution

A power controllable wireless communication device is developed, incorporating a variable gain amplifier, a reference power generation circuit, and a sensor circuit that generates a gain control signal based on ratios between reference powers and high-frequency signal powers, allowing for adjustments to maintain desired output power levels without the need for environmental change tables, thus reducing manufacturing costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electric power adjustment techniques are used to satisfy minimum output electric power requirements, then output power compliance is improved, but manufacturing cost increases

Engineering Contradiction:
Improveoutput power complianceVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent implements a feedback mechanism where the sensor circuit continuously monitors the output power level and provides feedback to the control circuit. The control circuit adjusts the gain of the variable gain amplifier based on this feedback to maintain the output power within the required range. This closed-loop feedback system ensures compliance with minimum output power requirements while avoiding complex power adjustment techniques, thereby reducing manufacturing costs.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs self-adjustment of output power through the interaction of the sensor circuit, control circuit, and variable gain amplifier. The sensor circuit automatically detects the actual output power level, and the control circuit autonomously generates appropriate gain control signals without requiring external intervention or complex adjustment mechanisms. This self-service capability ensures power compliance while simplifying the overall system and reducing manufacturing complexity.

Inventive Principle:
Principle #25Self-service

2Stability of the object's composition

If environmental change tables are created to adapt to environmental variations, then power stability is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improvepower stabilityVSAvoiddevice complexity
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent employs a dynamic adaptation mechanism where the system continuously monitors environmental changes through the sensor circuit and automatically adjusts the gain control signal in real-time. Instead of relying on pre-created environmental change tables, the system dynamically responds to environmental variations by continuously measuring output power and adjusting the variable gain amplifier accordingly. This dynamic approach maintains power stability while avoiding the complexity of storing and managing environmental lookup tables.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The feedback loop continuously monitors the actual output power level and automatically adjusts the gain control signal to compensate for environmental variations. The sensor circuit detects changes in output power caused by environmental factors, and the control circuit responds by adjusting the variable gain amplifier to maintain stable output. This real-time feedback mechanism provides power stability without requiring complex environmental change tables or pre-programmed adjustment data.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If multiple reference power levels are used for gain control, then power control precision is improved, but circuit complexity increases

Engineering Contradiction:
Improvepower control precisionVSAvoidcircuit complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent utilizes parameter changes in the reference power generation circuit to create multiple reference power levels dynamically. Instead of using fixed multiple reference power sources that would increase circuit complexity, the system generates different reference power levels by varying parameters such as resistance values or voltage levels in the reference power generation circuit. The control circuit selects appropriate reference power levels based on the required output power range, achieving precise power control while maintaining circuit simplicity through parameter variation rather than multiple complex circuits.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3119137B1Power controllable wireless communication device
Publication Date: 2019.08.07 DENSO CORP
  • EP3119137B1 patent drawingFigure 1
  • EP3119137B1 patent drawingFigure 2
  • EP3119137B1 patent drawingFigure 3

AI summary

POWER CONTROLLABLE WIRELESS COMMUNICATION DEVICE A power controllable wireless communication device MOD includes a variable gain amplifier PGA having a gain that can be controlled based on a gain control signal, a reference power generation circuit RPG, which generates first reference power and second reference power differing from the first reference power, a sensor circuit SCC supplied with selectively power of a high frequency signal output from the variable gain amplifier PGA, and the first reference power and the second reference power generated by the reference power generation circuit RPG, and a control circuit which generates the gain control signal based on a sensor output from the sensor circuit. When controlling power, the control circuit generates the gain control signal based on ratios among a first sensor output corresponding to the first reference power, a second sensor output corresponding to the second reference power, and a high frequency sensor output corresponding to the power of the high frequency signal.