Integrated Phase-Inverted Amplifier Without Balun

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Solution Overview

Problem

Conventional RF amplifiers with phase inversion functions have large circuit sizes and high power consumption due to the independent configuration of the LNA and PI circuits and the need for a balun before the differential converter circuit.

Innovation Solution

A phase inverted amplifier design utilizing an amplifying transistor, electronic switches, and a transformer with magnetically coupled windings to integrate the LNA and PI functions, reducing circuit size and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the LNA and phase inversion circuit are configured as independent circuit blocks with a balun before the differential converter, then the phase inversion function can be achieved, but the circuit size becomes large

Engineering Contradiction:
Improvephase inversion functionVSAvoidcircuit size
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent merges the LNA and phase inversion circuit into a single integrated circuit block. The amplifier transistor directly drives the electronic switches that perform phase inversion, eliminating the need for separate LNA and PI circuit blocks. This integration significantly reduces the overall circuit size while maintaining the phase inversion function.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent removes the balun component from the circuit configuration. By using electronic switches to directly invert the phase of the single-ended signal from the LNA, the design eliminates the need for a separate balun to convert to differential signals, thereby reducing circuit size and component count.

Inventive Principle:
Principle #2Taking out (Extraction)

2Reliability

If the LNA and phase inversion circuit are configured as independent circuit blocks, then the phase inversion function can be achieved, but power consumption increases

Engineering Contradiction:
Improvephase inversion functionVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The patent combines the LNA and phase inversion functions into one integrated circuit block, reducing the total power consumption. The electronic switches are directly controlled by the amplifier transistor output, eliminating the need for additional power-consuming components like separate PI circuit blocks and baluns.

Inventive Principle:
Principle #5Merging (Combining)

3Area of stationary object

If an integrated circuit configuration is used for the RF amplifier, then miniaturization is achieved, but the conventional independent block configuration is required which limits further size reduction

Engineering Contradiction:
Improvecircuit sizeVSAvoidcircuit configuration complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent integrates multiple functions (amplification and phase inversion) into a single circuit block with a simplified configuration. The amplifier transistor directly controls electronic switches that perform phase inversion, creating a compact design that is easier to implement as an integrated circuit compared to conventional independent block configurations.

Inventive Principle:
Principle #5Merging (Combining)

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 proposed design achieves a smaller circuit size and lower power consumption compared to conventional amplifiers, while maintaining phase inversion functionality.

Implementation Method 1

a transformer that includes a primary winding connected between two second ends of the two electronic switches, and a secondary winding that outputs an amplification signal from a first end

Methodology Applied
Scientific EffectMagnetic coupling: Electromagnetic Induction

Data Source

PatentEP4654470A1Phase inverted amplifier
Publication Date: 2025.11.26 FUJIKURA LTD
  • EP4654470A1 patent drawingFigure 1
  • EP4654470A1 patent drawingFigure 2A
  • EP4654470A1 patent drawingFigure 2B

AI summary

A phase inverted amplifier includes: an amplifying transistor that amplifies an input signal, two electronic switches each having a first end that is connected to an output end of the amplifying transistor, and that have ON/OFF states which are controlled by two control signals, and a transformer that includes a primary winding connected between two second ends of the two electronic switches, and a secondary winding that outputs an amplification signal from a first end.