Microstrip Circulator Ferrite-Ceramic Assembly for Low Insertion Loss

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Solution Overview

Problem

Current microstrip circulators and isolators face issues with poor magnetization, leading to increased insertion loss and intermodulation distortion, especially at higher frequencies, due to the use of organic adhesives and the difficulty in metallizing magnetic-dielectric assemblies, and the challenge of maintaining smoothness and uniformity in ferrite tile magnetization.

Innovation Solution

The integration of a ferrite disc, such as a yttrium iron garnet disc, into a dielectric substrate using an inorganic adhesive to form a composite structure, which is then metallized, providing improved magnetization and reducing the issues associated with organic adhesives, such as surface bumps and thermal instability, while allowing for the integration of additional components like couplers and amplifiers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If organic adhesive is used to secure ferrite disc in dielectric substrate, then assembly is easier, but magnetization quality deteriorates and surface uniformity is poor

Engineering Contradiction:

Improveassembly easeVSAvoidmagnetization uniformity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent changes the material parameter of the adhesive from organic to inorganic, which fundamentally alters the bonding characteristics and thermal properties. This parameter change enables better magnetization uniformity and surface smoothness while maintaining assembly feasibility, directly resolving the contradiction between ease of manufacture and manufacturing precision.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite structure using inorganic adhesive material that combines the benefits of strong bonding with magnetic material compatibility. This composite approach allows the adhesive to serve dual functions: structural bonding and magnetic field uniformity maintenance, thereby resolving the contradiction between assembly ease and magnetization quality.

Inventive Principle:

Principle #40Composite materials

2Stability of the object's composition

If ferrite tile is used, then magnetization can be achieved, but surface smoothness and uniformity deteriorate

Engineering Contradiction:

Improvemagnetization stabilityVSAvoidsurface uniformity

Core Design Contradiction:

Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The patent changes the adhesive material parameter from organic to inorganic, which fundamentally alters the bonding characteristics and thermal properties. This parameter change enables better magnetization uniformity and surface smoothness while maintaining assembly feasibility, directly resolving the contradiction between ease of manufacture and manufacturing precision.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses a dielectric substrate with an aperture that copies the ferrite disc geometry, allowing the ferrite disc to be securely held while maintaining a smooth outer surface. This copying approach preserves the magnetic properties while achieving the desired surface uniformity for metallization.

Inventive Principle:

Principle #26Copying

3Volume of moving object

If device size is reduced for 5G applications, then integration is improved, but magnetization quality and signal performance worsen

Engineering Contradiction:

Improvedevice volumeVSAvoidsignal performance

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent applies different material properties to different regions: the inorganic adhesive is specifically placed at the interface between ferrite disc and dielectric substrate to ensure local magnetization quality, while the overall device structure is minimized for 5G integration. This local quality approach maintains signal performance in a compact form factor.

Inventive Principle:

Principle #3Local quality

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

This approach enhances the magnetization of microstrip circulators and isolators, reducing insertion loss and intermodulation distortion, and enables the miniaturization of devices for 5G and higher frequency applications by using a dielectric tile substrate, allowing for the integration of multiple components on a single substrate.

Implementation Method 1

a ferrite disc secured within the aperture in the dielectric substrate

Methodology Applied

Scientific EffectFerromagnetism: Ferromagnetism

Implementation Method 2

an inorganic adhesive secures the ferrite disc within the aperture in the dielectric substrate

Methodology Applied

Scientific EffectAdhesion: Adhesive

Implementation Method 3

metallization on upper surfaces of the dielectric substrate and the ferrite disc

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentUS11843152B2Surface mount microstrip circulators using a ferrite and ceramic dielectric assembly substrate

Publication Date: 2023.12.12 SKYWORKS SOLUTIONS INC

AI summary

An integrated microstrip circulator comprises a dielectric substrate having an aperture, a ferrite disc secured within the aperture in the dielectric substrate, metallization on upper surfaces of the dielectric substrate and the ferrite disc, and surface mount contacts disposed on lower surfaces of the dielectric substrate and the ferrite disc and in electrical communication with the metallization on the upper surfaces of the dielectric substrate and the ferrite disc.