Dual-Mode Antenna Reflector Assembly for PIM Shielding

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing antenna assemblies struggle to integrate FDD and TDD components efficiently, particularly due to passive intermodulation (PIM) issues and electromagnetic shielding requirements, which are not optimally addressed in TDD components for FDD operation, complicating compact design and installation.

Innovation Solution

A reflector sub-assembly with integrated PCBs and radiators for FDD and TDD modes, featuring capacitive coupling and interleaved radiator arrangements, along with a housing sub-assembly for electromagnetic shielding, to create a compact and efficient antenna assembly.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If TDD components are integrated into a single antenna assembly with FDD components, then compact size is achieved, but electromagnetic shielding becomes insufficient leading to increased PIM

Engineering Contradiction:

Improveantenna assembly sizeVSAvoidpassive intermodulation (PIM)

Core Design Contradiction:

Volume of moving objectVSObject-affected harmful factors

Solution Approach 1:

The antenna assembly is segmented into distinct FDD and TDD sub-assemblies, each with dedicated radiators and feeding structures. This segmentation allows separate optimization of electromagnetic shielding for FDD while maintaining compact integration through shared reflector and housing structures.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A common reflector sub-assembly serves as an intermediary structure that supports both FDD and TDD radiators. The reflector provides electromagnetic shielding and structural support, enabling compact integration while maintaining performance requirements for both duplexing modes.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If FDD-specific electromagnetic shielding is implemented in TDD components, then PIM is reduced, but device complexity increases

Engineering Contradiction:

Improvepassive intermodulation (PIM)VSAvoidantenna assembly structure

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The reflector sub-assembly serves multiple functions: it acts as a common support structure for both FDD and TDD radiators, provides electromagnetic shielding, and enables compact integration. This multi-functionality reduces overall device complexity while maintaining PIM performance.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

FDD and TDD components are merged into a single integrated antenna assembly with shared housing and reflector structures. This merging reduces the number of separate assemblies needed while implementing FDD-specific shielding measures through the common structural elements.

Inventive Principle:

Principle #5Merging (Combining)

3Object-affected harmful factors

If separate antenna assemblies for FDD and TDD are used, then electromagnetic shielding is optimized, but installation complexity and space requirements increase

Engineering Contradiction:

Improvepassive intermodulation (PIM)VSAvoidinstallation ease

Core Design Contradiction:

Object-affected harmful factorsVSEase of operation

Solution Approach 1:

Separate FDD and TDD antenna assemblies are merged into a single integrated unit with common housing and reflector. This reduces installation complexity by requiring only one assembly location while maintaining optimized electromagnetic shielding through dedicated radiator structures for each duplexing mode.

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 solution enables a compact antenna design that reduces PIM, enhances uplink coverage, and supports both FDD and TDD modes by integrating TDD components optimized for FDD performance, reducing potential PIM sources and interfaces.

Implementation Method 1

The first PCB has a first PCB side directed towards the reflector and having a metallic layer thereon... arranged to cover the at least one reflector opening so as to prevent electromagnetic radiation from passing through

Methodology Applied

Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

a distant end facing away from the at least one first PCB and carrying at least one first radiating element... one or more second radiators... carrying at least one second radiating element

Methodology Applied

Scientific EffectElectromagnetic radiation: Electromagnetic Induction

Data Source

PatentUS12451594B2Antenna assembly supporting FDD and TDD operational modes and reflector sub-assembly thereof

Publication Date: 2025.10.21 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

A reflector sub-assembly for an antenna assembly configured to support FDD and TDD modes of operation is presented. The reflector sub-assembly comprises a reflector defining at least one reflector opening, and at least one first PCB arranged to cover the reflector opening having a first PCB side directed towards the reflector and with a metallic layer thereon and a second PCB side directed away from the reflector and comprising one or more first electric lines. The reflector sub-assembly also comprises an array of first radiators to support a TDD mode extending through the reflector opening and having a feeding end directed towards the first PCB and electrically connected to at least one of the first electric lines and a distant end facing away from the first PCB and carrying at least one first radiating element. The reflector sub-assembly further comprises one or more second radiators to support an FDD mode.