Inverted Doherty Amplifier Phase Correction for Wider Bandwidth

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Solution Overview

Problem

Existing Doherty-type power amplifiers face inefficiencies due to parasitic elements causing phase shifts between the main and peak amplifiers, leading to reduced bandwidth and increased insertion losses, which are not effectively addressed in current designs.

Innovation Solution

The proposed inverted Doherty-type amplifier device incorporates a distribution network with phase correction networks to compensate for phase shifts caused by parasitic elements, using a driver circuit and phase correction networks to adjust signal phases and combine signals in a way that maintains coherent RF waveforms and high efficiency, while allowing for unequal power distribution between the main and peak paths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional Doherty amplifiers are used, then signal amplification is achieved, but phase shifts caused by parasitic elements reduce bandwidth and increase insertion losses

Engineering Contradiction:
Improvephase coherenceVSAvoidbandwidth
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent inverts the traditional Doherty amplifier architecture by placing the main amplifier in the traditional peak path position and the peak amplifier in the traditional main path position. This inversion, combined with specific phase correction network configurations, compensates for parasitic-induced phase shifts and extends bandwidth while maintaining phase coherence between the two amplifier paths.

Inventive Principle:
Principle #13The other way round (Inversion)

Solution Approach 2:

The patent introduces phase correction networks as intermediary components between the amplifiers and the combiner. These networks actively compensate for phase shifts caused by parasitic elements, ensuring that signals from both amplifier paths remain coherent across a broader frequency range, thus resolving the bandwidth limitation without sacrificing phase coherence.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Loss of energy

If unequal power distribution is used between main and peak paths, then efficiency is improved, but phase alignment becomes more difficult

Engineering Contradiction:
Improvepower-added efficiencyVSAvoidphase alignment precision
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The patent employs dynamic phase correction networks that can adjust their phase shift characteristics to compensate for the phase differences introduced by unequal power distribution between the main and peak amplifiers. This dynamic adjustment maintains precise phase alignment across varying operating conditions, enabling efficient unequal power distribution without sacrificing phase coherence.

Inventive Principle:
Principle #15Dynamics

3Reliability

If phase correction networks are added, then phase coherence is maintained, but device complexity increases

Engineering Contradiction:
Improvephase coherenceVSAvoidcircuit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the phase correction functionality with the existing amplifier and distribution network structures. By integrating phase correction networks into the signal paths and utilizing the inverted architecture, the design maintains phase coherence while minimizing additional complexity compared to traditional approaches that would require separate, dedicated phase correction stages.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4456419A1Inverted doherty-type amplifier device
Publication Date: 2024.10.30 INFINEON TECHNOLOGIES AG
  • EP4456419A1 patent drawingFigure 1
  • EP4456419A1 patent drawingFigure 2
  • EP4456419A1 patent drawingFigure 3a~3c

AI summary

An inverted Doherty-type amplifier device comprises a distribution network comprising a first signal port for providing a first signal for a main path of the inverted Doherty-type amplifier from a received input signal and a second signal port for providing a second signal for a peak path of the inverted Doherty-type amplifier device from the received input signal. The device comprises a first amplifier coupled in the main path and coupled to the first signal port, configured to amplify a received signal to obtain a first amplified signal. The device comprises a first phase correction network coupled to the second signal port and coupled to adjust a phase of a received signal to obtain a phase corrected second signal. A second amplifier is coupled to an output of the first phase correction network and is configured to amplify a received signal to obtain a second amplified signal. A second phase correction network is coupled to an output for the second amplifier and configured to adjust a phase of a received signal to obtain a phase corrected second amplified signal. A signal combiner has a first input coupled to an output of the first amplifier and a second input coupled to an output of the second phase correction network, the signal combiner configured to combine a signal that is based on the first amplified signal and a signal that is based on the phase corrected second amplified signal to obtain a combined signal.