TDD Transceiver Bias Control Using Guard-Interval Feedback

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Solution Overview

Problem

Conventional transceivers face challenges in continuously controlling bias voltage for RF power amplifiers due to varying system parameters, such as temperature changes, which affects the desired operating properties, especially during transmission operations where measuring quiescent drain current is difficult.

Innovation Solution

Implementing a bias voltage control loop that is activated during guard intervals in time division multiplexing operations, allowing for continuous adjustment of the bias voltage to maintain optimal amplifier performance by deactivating the control loop during signal transmission and reception.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the bias voltage control loop is activated continuously, then the amplifier performance can be maintained optimally, but the measurement of quiescent drain current becomes difficult during transmission operation

Engineering Contradiction:

Improveamplifier performance consistencyVSAvoidquiescent drain current measurement

Core Design Contradiction:

ReliabilityVSDifficulty of detecting and measuring

Solution Approach 1:

The bias voltage control loop is activated periodically during guard intervals rather than continuously. The loop controller switches the control loop between active and inactive states, enabling measurements during transmission-free periods while maintaining amplifier performance through periodic adjustments.

Inventive Principle:

Principle #19Periodic action

2Measurement precision

If the bias voltage control loop is deactivated during transmission and reception, then accurate measurements can be performed, but continuous control is lost

Engineering Contradiction:

Improvequiescent drain current measurement accuracyVSAvoidcontrol responsiveness

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The control loop operates periodically during guard intervals, which are natural pauses in the transmission-reception cycle. This timing allows precise measurements without RF interference while maintaining system productivity through timely updates of bias voltage settings.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The bias voltage is adjusted in advance during guard intervals before the next transmission period begins. This preliminary adjustment ensures the amplifier is properly biased for upcoming transmission, maintaining performance without requiring continuous control during active transmission.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If adaptive biasing is implemented to compensate for parameter changes, then amplifier properties are maintained, but the complexity of the control system increases

Engineering Contradiction:

Improvecompensation for temperature and drift changesVSAvoidcontrol loop structure

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The control loop measures the actual quiescent drain current and compares it with a reference value, then adjusts the bias voltage accordingly. This feedback mechanism enables automatic compensation for temperature changes and component drift without requiring complex external control systems.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The amplifier system performs its own self-diagnosis and self-adjustment by measuring its own quiescent current and automatically correcting bias voltage deviations. This self-service capability maintains amplifier performance without requiring external monitoring or complex control infrastructure.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS10958224B2Method and device for providing a bias voltage in transceivers operating in time division multiplexing operation

Publication Date: 2021.03.23 INFINEON TECHNOLOGIES AG

AI summary

Devices and methods for generating a bias voltage for a transceiver operating in time division multiplexing operation, and corresponding transceivers are provided. In this case, the bias voltage is controlled in guard intervals between transmission and reception of signals by the transceiver.