Acoustic Wave Filter Layout for Simultaneous-Band RF Modules
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Solution Overview
Problem
Conventional high frequency modules face challenges in maintaining performance during simultaneous communication due to the difficulty in placing filters close to the switch, leading to degradation of characteristics.
Innovation Solution
A high frequency module design with a mounting substrate, antenna terminal, and switch, where filters with specific acoustic wave resonators are positioned to minimize impedance changes and reduce parasitic capacitance, allowing for closer proximity to the switch and improved signal path efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If filters are placed closer to the switch, then signal path efficiency is improved and impedance changes are reduced, but device layout complexity increases due to the need for precise positioning of multiple resonators
Solution Approach 1:
The filter is divided into multiple independent acoustic wave resonators (first antenna end resonator, second antenna end resonator, and other resonators) that can be positioned separately on the mounting substrate. This segmentation allows each resonator to be optimally placed to minimize impedance changes while maintaining the overall filter function.
Solution Approach 2:
Different resonators are positioned at specific locations relative to the switch and antenna terminal. The first antenna end resonator is placed on the first signal path closest to the antenna terminal, while the second antenna end resonator is placed on the second signal path closest to the antenna terminal, creating local optimizations that collectively improve simultaneous communication characteristics.
2Reliability
If filters are positioned closer to the switch, then parasitic capacitance is reduced, but manufacturing precision requirements increase for maintaining optimal distances
Solution Approach 1:
The patent utilizes the two-dimensional plane of the mounting substrate to position resonators at optimal distances from the switch and antenna terminal. By distributing resonators across different signal paths and locations on the substrate plane, the design achieves reduced parasitic capacitance while providing manufacturing tolerance through spatial distribution rather than requiring extreme precision at single critical points.
Solution Approach 2:
The resonators are pre-positioned on the mounting substrate during the substrate fabrication process before final component assembly. This preliminary positioning ensures optimal distances are achieved while allowing standard manufacturing tolerances, as the resonator locations are determined during substrate manufacturing rather than requiring post-assembly adjustment.
3Temperature
If multiple resonators are distributed across different locations, then heat dissipation is improved, but device area increases
Solution Approach 1:
Multiple resonators are distributed across the two-dimensional plane of the mounting substrate, utilizing available space efficiently. By arranging resonators along different signal paths and utilizing the substrate's planar area, the design achieves improved heat dissipation through spatial distribution while minimizing the overall area increase compared to a concentrated layout.
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 effectively suppresses the degradation of characteristics during simultaneous communication by reducing impedance changes and loss, enhancing the module's performance and heat dissipation capabilities.
Implementation Method 1
The first filter has a plurality of first acoustic wave resonators. The second filter has a plurality of second acoustic wave resonators.
Implementation Method 2
Each of the plurality of filters is an acoustic wave filter, and each of the plurality of series arm resonators and the plurality of parallel arm resonators includes an acoustic wave resonator.
Data Source
AI summary
In a high frequency module, a plurality of filters is connected to an antenna terminal with a switch interposed. The plurality of filters includes a first filter that has a pass band including a frequency band of a first communication band and a second filter that has a pass band including a frequency band of a second communication band that is capable of simultaneous communication with the first communication band. A first electronic component having the first filter and a second antenna end resonator of the second filter is disposed on a first principal surface of the mounting substrate. A second electronic component having at least one second acoustic wave resonator other than a second antenna end resonator of the second filter is disposed on the first principal surface of the mounting substrate.