RF Module Switch Control Circuit Placement for Isolation
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Solution Overview
Problem
In small-sized radio-frequency modules, the close proximity of signal paths on the input and output sides of the power amplifier leads to deteriorated isolation, resulting in unwanted feedback loops and unstable operation of the power amplifier.
Innovation Solution
A radio-frequency module configuration where the first and second switches, and the switch control circuit are integrated into a semiconductor IC, with the switch control circuit positioned between the switches, effectively reducing electromagnetic field coupling and maintaining isolation between signal paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the radio-frequency module is miniaturized, then the size is reduced, but the isolation between input and output signal paths deteriorates
Solution Approach 1:
The module is divided into distinct functional regions: a first region containing the input signal path components (LNA, input switch) and a second region containing the output signal path components (PA, output switch). This spatial segmentation prevents electromagnetic coupling between input and output paths while maintaining a compact overall size.
Solution Approach 2:
The patent utilizes three-dimensional space by mounting different components on different surfaces of the module substrate. The LNA and input switch are mounted on a first surface, while the PA and output switch are mounted on a second surface opposite to the first surface, creating vertical separation that maintains isolation in a small footprint.
2Area of stationary object
If the signal paths are placed close together to reduce size, then the module area is reduced, but feedback loops form causing unstable operation
Solution Approach 1:
The module is divided into distinct functional regions: a first region containing the input signal path components (LNA, input switch) and a second region containing the output signal path components (PA, output switch). This spatial segmentation prevents electromagnetic coupling between input and output paths while maintaining a compact overall size.
Solution Approach 2:
Grounded via holes are introduced as intermediary elements between the input and output signal paths. These via holes provide electromagnetic shielding and prevent direct coupling between the closely spaced signal paths, eliminating feedback loops while allowing compact layout.
3Device complexity
If components are integrated into a single chip, then the device complexity is reduced, but heat dissipation becomes difficult
Solution Approach 1:
The module is divided into distinct functional regions: a first region containing the input signal path components (LNA, input switch) and a second region containing the output signal path components (PA, output switch). This spatial segmentation prevents electromagnetic coupling between input and output paths while maintaining a compact overall size.
Solution Approach 2:
The patent utilizes three-dimensional space by mounting different components on different surfaces of the module substrate. The LNA and input switch are mounted on a first surface, while the PA and output switch are mounted on a second surface opposite to the first surface, creating vertical separation that maintains isolation in a small footprint.
Data Source
AI summary
A radio-frequency module includes a module substrate; a power amplifier; a first switch connected to an input terminal of the power amplifier; a second switch connected to an output terminal of the power amplifier; and a switch control circuit that controls the first switch and the second switch. The first switch, the second switch, and the switch control circuit are included in a semiconductor IC being integrated into a single chip. The power amplifier and the semiconductor IC are mounted on or above the module substrate. When the module substrate is viewed in a plan view, in the semiconductor IC, the switch control circuit is disposed between the first switch and the second switch.