Transformer-Based Antenna Switching Network for 5G

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing antenna switching networks in wireless communication systems, particularly for 5G, suffer from significant power leakage due to off-capacitance in switch transistors, leading to inefficiencies in millimeter wave frequencies.

Innovation Solution

A transformer-based antenna switching network is introduced, utilizing a transformer with a primary and secondary winding, and switch transistors coupled to the secondary winding to selectively couple antennas, minimizing power leakage by resonating out off-capacitance and matching impedances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If switch transistors are used for antenna switching, then antenna selection is enabled, but power leakage occurs due to off-capacitance

Engineering Contradiction:
Improveantenna selection capabilityVSAvoidpower leakage
Core Design Contradiction:
Adaptability or versatilityVSLoss of energy

Solution Approach 1:

A transformer is introduced as an intermediary component between the switch transistors and the antennas. The transformer couples to the secondary winding of the switch network and provides impedance transformation, which reduces the impact of off-capacitance leakage from the switch transistors. This intermediary structure allows the switch transistors to perform antenna selection while the transformer minimizes the power leakage caused by their off-capacitance.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the impedance parameters in the switching network by introducing a transformer with specific turns ratio. By transforming the impedance seen by the switch transistors, the operating conditions are optimized to reduce power leakage. The transformer modifies the electrical parameters (impedance, voltage, current) in the circuit to minimize the harmful effects of off-capacitance while maintaining antenna switching functionality.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If traditional switching networks are used, then antenna switching is achieved, but efficiency is poor at millimeter wave frequencies

Engineering Contradiction:
Improveantenna switching functionVSAvoidsystem efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent optimizes the electrical parameters of the switching network by incorporating a transformer designed for millimeter wave frequencies. The transformer's impedance transformation capability is specifically tuned to improve efficiency at these high frequencies, where traditional switching networks suffer from significant losses. This parameter optimization enables effective antenna switching while maintaining high system efficiency at millimeter wave frequencies.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The transformer serves as a mediator that adapts the switching network to operate efficiently at millimeter wave frequencies. It provides the necessary impedance matching and signal coupling that traditional direct-switching architectures cannot achieve at these high frequencies, thereby improving overall system productivity and efficiency.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If switch transistors with off-capacitance are used, then antenna switching is possible, but power leakage is significant

Engineering Contradiction:
Improveantenna switching operationVSAvoidpower leakage
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The transformer is positioned as an intermediary between the easily operable switch transistors and the antennas. It maintains the ease of operation provided by the switch transistors while simultaneously reducing the power leakage caused by their off-capacitance through impedance transformation and proper coupling.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful effect of off-capacitance into a manageable parameter by using the transformer to transform the impedance seen by the switch transistors. The off-capacitance, which would normally cause significant power leakage, is transformed along with the other electrical parameters, and its harmful effect is minimized through proper transformer design and impedance matching.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 transformer-based network reduces power leakage and improves efficiency by inversely proportional on-resistance, allowing for effective antenna selection and isolation, even at millimeter wave frequencies.

Implementation Method 1

a first transformer including a primary winding and a secondary winding, wherein the primary winding of the first transformer is operably coupled to a power amplifier

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

minimizing power leakage by resonating out off-capacitance

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 3

switch transistors coupled to the secondary winding to selectively couple antennas

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 4

matching impedances

Methodology Applied
Scientific EffectElectrical impedance matching: Electrical Resistance

Data Source

PatentEP4042574B1Transformer-based antenna switching network
Publication Date: 2026.03.18 QUALCOMM INC
  • EP4042574B1 patent drawingFigure 1A
  • EP4042574B1 patent drawingFigure 1B
  • EP4042574B1 patent drawingFigure 1C

AI summary

A transformer-based antenna switching network includes a transformer having a secondary winding that extends between a first terminal and a second terminal. The first terminal couples to ground through a first switch and connects to a first antenna. The second terminal couples to ground through a second switch and connects to a second antenna.