Antenna Matching Calibration for Multichannel Transmitter Efficiency

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Solution Overview

Problem

Conventional portable radio transceivers face inefficiencies in transmitter power consumption due to impedance mismatch between the transmitter and antenna, leading to high voltage standing wave ratios and increased power consumption, especially in multichannel systems where adjacent channel operations affect amplifier efficiency.

Innovation Solution

A calibration process for portable multichannel transceivers that varies tuning parameters of antenna matching networks to determine optimized tuning control data for both active and inactive transmitters, storing this data for operational mode use, ensuring optimal impedance matching and reduced RF amplifier load current.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional impedance matching methods are used with fixed transmitter output impedance, then the system structure remains simple, but the voltage standing wave ratio increases and power efficiency deteriorates due to impedance mismatch with the antenna

Engineering Contradiction:
Improvetransmitter power consumptionVSAvoidimpedance matching system complexity
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent implements dynamic impedance matching by making the matching network adjustable and adaptive. The system varies tuning parameters of the antenna matching network based on detected operating conditions (frequency, power level, antenna VSWR) to maintain optimal impedance match across different transmit scenarios, thereby reducing power consumption while managing system complexity through controlled adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system employs feedback mechanisms where the controller detects antenna VSWR, transmitter power level, and operating frequency, then uses this information to adjust the antenna matching network tuning parameters. This closed-loop feedback approach optimizes power efficiency by continuously adapting the impedance match to current operating conditions without requiring overly complex open-loop control systems.

Inventive Principle:
Principle #23Feedback

2Loss of energy

If antenna matching network tuning parameters are adjusted to achieve optimal impedance match, then power efficiency improves, but the difficulty of detecting and measuring optimal tuning conditions increases

Engineering Contradiction:
Improvereflected powerVSAvoidoptimal tuning condition detection
Core Design Contradiction:
Loss of energyVSDifficulty of detecting and measuring

Solution Approach 1:

The controller detects antenna VSWR and uses this feedback to determine optimal tuning parameters for the antenna matching network. The system measures reflected power and forward power to calculate VSWR, then adjusts tuning parameters to minimize VSWR and maximize power transfer efficiency, solving the detection difficulty through systematic measurement and feedback control.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces manual or mechanical tuning methods with electronic control of the antenna matching network. The controller electronically adjusts tuning parameters based on detected VSWR conditions, eliminating the need for complex mechanical tuning mechanisms and simplifying the detection and measurement process through electronic sensing and control.

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

3Power

If the transmitter operates at high power levels to meet communication requirements, then the communication performance improves, but the battery life decreases due to increased power consumption

Engineering Contradiction:
Improvetransmitter output powerVSAvoidbattery life
Core Design Contradiction:
PowerVSDuration of action of moving object

Solution Approach 1:

The system dynamically changes operating parameters including antenna matching network tuning parameters, transmitter power level, and operating frequency to optimize the balance between communication performance and power consumption. By adjusting these parameters based on detected conditions, the system achieves required communication performance while minimizing power consumption to extend battery life.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements dynamic operation where the transmitter adapts its power level and matching network tuning in real-time based on communication requirements and battery status. This dynamic adjustment allows the system to use high power only when necessary for communication performance while operating at lower power levels during normal conditions, thereby extending battery life while meeting communication requirements.

Inventive Principle:
Principle #15Dynamics

4Adaptability or versatility

If multiple transmitters operate simultaneously in a multichannel system, then the system versatility improves, but the impedance matching becomes more difficult due to interactions between adjacent channel transmitters

Engineering Contradiction:
Improvemultichannel operation capabilityVSAvoidimpedance matching complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by independently optimizing the impedance matching for each transmitter channel while accounting for interactions with adjacent channels. The controller detects VSWR and operating conditions for each channel separately and adjusts the matching network tuning parameters locally for each transmitter, allowing versatile multichannel operation while managing complexity through localized optimization rather than requiring a completely new complex matching system.

Inventive Principle:
Principle #3Local quality

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 approach enhances energy efficiency by minimizing RF amplifier load current and reflected power, extending battery life in portable transceivers by maintaining optimal impedance matching across varying transmit scenarios and frequencies.

Implementation Method 1

Maximum power transfer from the final output stage of the transmitter to the antenna occurs when the output impedance of the transmitter is matched to the input impedance of the antenna

Methodology Applied
Scientific EffectImpedance matching: Electrical Impedance Tomography

Implementation Method 2

a sensing mechanism such as a directional coupler can be used to detect the VSWR at an antenna port. The directional coupler can detect forward and reflected signals on a transmission line associated with an antenna feed

Methodology Applied
Scientific EffectElectromagnetic signal detection: Electromagnetic Induction

Implementation Method 3

the greatest source of power consumption usually can be found in the final amplifier stage which increases low level radio frequency (RF) exciter signals to much higher power levels

Methodology Applied
Scientific EffectSignal amplification: Magnetic Amplifier

Data Source

PatentEP3244541B1Transmitter efficiency optimization
Publication Date: 2020.03.11 L3HARRIS GLOBAL COMMUNICATIONS INC
  • EP3244541B1 patent drawingFigure 1
  • EP3244541B1 patent drawingFigure 2
  • EP3244541B1 patent drawingFigure 3

AI summary

Radio transceiver efficiency is improved by operations involving a calibration mode and an operating mode. The calibration mode includes a first calibration to determine a first optimized tuning control data for a first antenna matching network of a first transmitter when a second transmitter of the portable transceiver system inactive. A second calibration of the first antenna matching network while the second transmitter is active to determine second optimized tuning control data. In operational mode the first optimized tuning control data is used when the second transmitter is not active. The second optimized tuning control data is used when the second transmitter is active.