Multilayer RF Module Grounding Layout for Circuit Isolation

Solution Overview

Problem

Existing high-frequency modules for mobile wireless terminals are bulky due to the need for terminating resistors and increased constituent elements, which complicates the isolation of transmission and reception circuits connected to multiple antennas.

Innovation Solution

A compact high-frequency module design featuring a multilayer body with integrated switch elements and filter components, where switching connection terminals not connected to the filter circuit are directly connected to an inner layer ground electrode via conductive via holes, reducing parasitic inductance and enhancing isolation characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If terminating resistors and routing electrodes are added to secure isolation between transmission and reception circuits, then isolation performance is improved, but module size and device complexity increase

Engineering Contradiction:

Improveisolation performanceVSAvoidmodule size

Core Design Contradiction:

ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent merges the isolation function into the ground electrode structure itself. The ground electrode is designed to be positioned between the transmission and reception circuits, combining the grounding function with the isolation function. This eliminates the need for separate terminating resistors and routing electrodes, achieving isolation performance while reducing module size.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The ground electrode serves multiple functions simultaneously: it provides electrical grounding for the switch elements and actively isolates the transmission and reception circuits through its strategic positioning. This multi-functional design replaces what would traditionally require separate isolation components, reducing overall device complexity and size.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If terminating resistors and routing electrodes are added to secure isolation between transmission and reception circuits, then isolation performance is improved, but device complexity increases

Engineering Contradiction:

Improveisolation performanceVSAvoidnumber of constituent elements

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the isolation function into the ground electrode structure itself. The ground electrode is designed to be positioned between the transmission and reception circuits, combining the grounding function with the isolation function. This eliminates the need for separate terminating resistors and routing electrodes, achieving isolation performance while reducing module size.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The ground electrode serves multiple functions simultaneously: it provides electrical grounding for the switch elements and actively isolates the transmission and reception circuits through its strategic positioning. This multi-functional design replaces what would traditionally require separate isolation components, reducing overall device complexity and size.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Data Source

PatentUS9413413B2High-frequency module

Publication Date: 2016.08.09 MURATA MFG CO LTD

AI summary

A high-frequency module includes a first switch element and a second switch element that are mounted on a multilayer body. The first switch element includes a common terminal and individual terminals. The second switch element includes a common terminal and individual terminals. The individual terminals are connected to any of SAW filters mounted on the multilayer body or low loss filters provided inside the multilayer body. The individual terminals are grounded by being connected to an inner layer ground electrode inside the multilayer body by conductive via holes.