RF Module Shield Plate Layout for Multi-Band Signal Isolation
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Solution Overview
Problem
In mobile communication devices, the complexity of radio-frequency front-end circuits leads to issues such as harmonic waves from high-power transmit signals degrading the quality of both transmit and receive signals, and weak isolation between transmit and receive paths due to electromagnetic coupling, resulting in degraded receive sensitivity.
Innovation Solution
A radio-frequency module with a module substrate, power amplifiers, filters, a resin member, a metal shield layer, and metal shield plates that inhibit electromagnetic field coupling between different communication bands, thereby reducing signal degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If multiple power amplifiers are disposed close together on the module substrate to reduce device size, then device compactness is improved, but electromagnetic field coupling between amplifiers increases causing signal quality degradation
Solution Approach 1:
Ground electrodes are introduced as intermediary elements between adjacent power amplifiers. These ground electrodes act as shields that redirect electromagnetic fields, preventing direct coupling between amplifiers while maintaining compact spacing. The ground electrodes are connected to the ground potential through conductive structures, creating an electromagnetic barrier that isolates adjacent amplifiers.
Solution Approach 2:
The module substrate is segmented into distinct electromagnetic zones by introducing ground electrodes and conductive structures between power amplifiers. This segmentation divides the continuous electromagnetic field into isolated regions, allowing multiple amplifiers to operate closely without mutual interference. The segmentation creates electromagnetic compartments that maintain signal integrity.
2Power
If transmit power is increased to improve communication range, then transmission distance is improved, but harmonic waves from the high-power signal degrade transmit and receive signal quality
Solution Approach 1:
Harmonic waves are extracted and removed from the transmit signal path using filtering structures. The patent introduces conductive structures and ground electrodes that form electromagnetic shields, which selectively block harmonic frequency components while allowing the fundamental transmit frequency to pass. This extraction of harmful harmonic components enables high-power transmission without signal quality degradation.
Solution Approach 2:
The ground electrodes and conductive structures are positioned to convert harmful electromagnetic radiation into beneficial shielding effects. By strategically placing these structures, the patent transforms potential sources of interference into protective barriers that redirect electromagnetic energy away from sensitive circuits, thereby enabling high-power operation.
3Area of stationary object
If inductors in transmit and receive paths are positioned close together to reduce area, then area utilization is improved, but isolation between transmit and receive sides becomes weak allowing signal leakage
Solution Approach 1:
Ground electrodes are introduced as intermediary shielding elements between inductors in transmit and receive paths. These ground electrodes create electromagnetic barriers that prevent direct coupling between the inductors, maintaining strong isolation despite close physical proximity. The ground electrodes are connected to ground potential, effectively blocking signal leakage between paths.
4Device complexity
If circuit elements are densely arranged to improve integration, then device complexity is reduced, but electromagnetic coupling between elements increases causing signal degradation
Solution Approach 1:
The densely arranged circuit elements are segmented into isolated electromagnetic zones using ground electrodes and conductive structures. These segmentation elements create electromagnetic compartments that allow high integration density while preventing harmful coupling between adjacent elements. Each circuit element operates within its own electromagnetic boundary.
Solution Approach 2:
Ground electrodes serve as intermediary shielding structures between densely packed circuit elements. These intermediaries redirect electromagnetic fields and prevent direct coupling between adjacent elements, enabling high integration without signal degradation. The ground electrodes are strategically positioned to maximize isolation while minimizing space consumption.
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 effectively reduces the deterioration of transmit and receive signal quality by minimizing electromagnetic interference and enhancing isolation between different communication bands, thereby improving the overall performance of the radio-frequency module.
Implementation Method 1
a metal shield layer that covers a surface of the resin member and that is set at a ground potential, a first metal shield plate disposed on the first major surface between the first power amplifier and the second power amplifier
Data Source
AI summary
A radio-frequency module includes power amplifiers on a major surface of a module substrate, a transmit filter coupled to an output terminal of the power amplifier to pass a transmit signal in a communication band A, a transmit filter coupled to an output terminal of the power amplifier to pass a transmit signal in a communication band C, a transmit filter coupled to an output terminal of the power amplifier to pass a transmit signal in a communication band E, a resin member covering the major surface, a metal shield layer covering a surface of the resin member, and a metal shield plate on the major surface between the power amplifier and the power amplifier and also between the power amplifier and the power amplifier. The metal shield plate is in contact with a first ground electrode at the major surface and also with the metal shield layer.