High-Frequency Module Isolation via Vertical Stacking and Ground Electrodes
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Solution Overview
Problem
Existing high-frequency modules fail to maintain sufficient isolation between transmission and reception circuits, particularly when using SAW duplexers that multiplex and demultiplex signals, leading to reduced isolation due to inadequate mounting and wiring patterns.
Innovation Solution
A high-frequency module design with a multilayer body that mounts a switch IC and SAW duplexers on specific surfaces, with external connection lands arranged to ensure spacing and grounding, preventing electromagnetic field coupling by using via holes and ground electrodes to separate transmission and reception circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If external connection terminals are aligned and formed on opposing side surfaces to ensure isolation, then isolation between transmission and reception circuits is improved, but the wiring pattern and mounting pattern still allow isolation reduction through proximity coupling
Solution Approach 1:
The patent transitions from two-dimensional planar arrangement to three-dimensional vertical stacking. The multilayer body structure allows transmission and reception circuits to be positioned at different heights (different layers), achieving isolation in the vertical dimension rather than only in the planar view. This resolves the contradiction by providing spatial separation without complicating the wiring pattern, as via holes provide direct vertical connections.
Solution Approach 2:
The patent introduces ground electrodes as intermediary elements positioned between the transmission and reception circuits. These ground electrodes act as shields that prevent electromagnetic coupling between the circuits, maintaining isolation without requiring complex wiring patterns. The ground electrodes serve as a mediating structure that enables close proximity of circuits while maintaining electrical isolation.
2Adaptability or versatility
If SAW duplexers are used to multiplex and demultiplex signals, then frequency band utilization is improved, but isolation between transmission and reception circuits deteriorates
Solution Approach 1:
The patent positions SAW duplexers at different vertical levels in the multilayer body, separating transmission-side SAW duplexers from reception-side SAW duplexers in the layer direction. This vertical separation in the third dimension prevents electromagnetic coupling between the duplexers while maintaining their frequency multiplexing function, thus resolving the isolation deterioration caused by SAW duplexer proximity.
Solution Approach 2:
The patent introduces ground electrodes as intermediary shielding elements positioned between transmission-side and reception-side SAW duplexers. These ground electrodes act as electromagnetic shields that prevent coupling between the duplexers, allowing the SAW duplexers to maintain their signal multiplexing capability while preserving isolation between transmission and reception circuits.
3Volume of moving object
If transmission and reception circuits are superposed on one another to save space, then device compactness is improved, but isolation between circuits deteriorates
Solution Approach 1:
The patent utilizes the vertical dimension (layer direction) to separate transmission and reception circuits while maintaining compactness in the planar view. By stacking circuits at different heights in the multilayer body, the design achieves three-dimensional space utilization that reduces overall module volume while preventing circuit superposition that would cause coupling. The via holes provide efficient vertical interconnection without requiring large planar distances.
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 design achieves significant isolation between transmission and reception circuits, preventing interference and ensuring reliable signal processing even with SAW duplexers, thereby enhancing the module's performance.
Implementation Method 1
The high-frequency module includes multiple duplexers each including a pair of surface acoustic wave (SAW) filters
Implementation Method 2
A reception side mounting land where a reception signal side port of the SAW duplexer is mounted is connected to the reception side external connection land substantially only via via holes
Implementation Method 3
ground electrodes are provided between the reception side external connection land and the transmission side external connection land
Data Source
AI summary
In a high frequency module, mounting lands for reception signal output side ports of SAW duplexers, respectively, on a top surface of a multilayer body are arranged so as to be superposed on reception side external connection lands on a bottom surface of the multilayer body along the layer direction and the mounting lands are directly connected to the reception side external connection lands via holes. Transmission side external connection lands are located on the bottom surface of the multilayer body. The transmission side external connection lands are connected to mounting lands for transmission signal input side ports on the top surface of the multilayer body via certain inner layer electrodes that do not come close to the via holes of the reception system and the via holes.