RF Module Board Layout to Prevent Power Amplifier Oscillation
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Solution Overview
Problem
The existing radio frequency module configurations in small-sized front-end circuits experience unstable operations due to electric field, magnetic field, or electromagnetic field coupling between radio frequency components, leading to unnecessary feedback loops and oscillation of transmission power amplifiers.
Innovation Solution
The radio frequency module is designed with a configuration where first circuit components are mounted on one principal surface of the module board and second circuit components are mounted on the opposite surface, effectively reducing coupling and preventing oscillation by arranging them with the module board interposed between the input and output sides of the transmission power amplifiers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If radio frequency components are disposed in a compact front-end circuit module, then the device size is reduced and integration is improved, but electric field coupling, magnetic field coupling, or electromagnetic field coupling occurs between input side components and output side components, causing transmission power amplifier oscillation and unstable operation
Solution Approach 1:
The patent applies dimensionality change by transitioning from a planar two-dimensional layout to a three-dimensional stacked configuration. Circuit components are arranged on multiple layers (first layer, second layer, third layer) of the module board, with the transmission power amplifier on the first layer, input side components on the second layer, and output side components on the third layer. This vertical stacking reduces horizontal coupling between components while maintaining compact overall size, thereby resolving the contradiction between miniaturization and operational stability.
Solution Approach 2:
The patent introduces an intermediary shielding structure (ground shield layer) positioned between the input side radio frequency components and the transmission power amplifier. This intermediary layer acts as an electromagnetic barrier that blocks or attenuates coupling fields, preventing harmful electromagnetic interference from reaching the power amplifier and causing oscillation, thus maintaining stable operation in the compact module design.
2Device complexity
If radio frequency components are arranged closely to reduce module size, then integration density is improved, but unnecessary feedback loops are formed causing transmission power amplifier oscillation
Solution Approach 1:
The patent resolves the feedback loop issue by arranging components in three-dimensional space across multiple layers. The transmission power amplifier is placed on the first layer, input side components on the second layer, and output side components on the third layer, with vertical interconnections via conductive vias. This spatial separation in the vertical dimension breaks potential feedback paths that would exist in a planar arrangement, allowing high integration density without causing oscillation.
Solution Approach 2:
The patent employs a ground shield layer as an intermediary barrier positioned between the input side components and the transmission power amplifier. This intermediary structure interrupts unwanted electromagnetic coupling and blocks feedback signal paths, preventing the formation of oscillatory feedback loops while maintaining the compact integrated design.
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
This configuration significantly reduces unstable operations of the transmission power amplifiers by minimizing electric, magnetic, or electromagnetic field coupling, thereby maintaining stable operation and improving signal quality and reception sensitivity.
Implementation Method 1
electric field coupling, magnetic field coupling, or electromagnetic field coupling occurs between a radio frequency component (e.g., the above-described switch) disposed on the input side of the transmission power amplifier and a radio frequency component disposed on the output side of the transmission power amplifier
Implementation Method 2
electric field coupling, magnetic field coupling, or electromagnetic field coupling occurs between a radio frequency component (e.g., the above-described switch) disposed on the input side of the transmission power amplifier and a radio frequency component disposed on the output side of the transmission power amplifier
Implementation Method 3
electric field coupling, magnetic field coupling, or electromagnetic field coupling occurs between a radio frequency component (e.g., the above-described switch) disposed on the input side of the transmission power amplifier and a radio frequency component disposed on the output side of the transmission power amplifier
Data Source
AI summary
A radio frequency module includes: a module board including a first principal surface and a second principal surface on opposite sides of the module board, a transmission input terminal, an antenna connection terminal, and a transmission power amplifier. At least one of one or more first circuit components that are disposed on a transmission input path connecting the transmission input terminal and the transmission power amplifier is mounted on the first principal surface, and at least one of one or more second circuit components that are disposed on a first transmission output path or a second transmission output path each connecting an output terminal of the transmission power amplifier and the antenna connection terminal is mounted on the second principal surface.