RF Module Control Circuit Placement for Signal Quality
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Solution Overview
Problem
In small transceiver modules, the digital control signal from the control circuit can cause spurious signals in adjacent channels, leading to deterioration of the adjacent channel leakage ratio (ACLR) and transmission signal quality when using a power amplifying module as a transmission circuit.
Innovation Solution
A radio frequency module configuration where the control circuit and switches are disposed on opposite surfaces of a module board, with the control circuit on one surface and switches on the other, to suppress electric field, magnetic field, or electromagnetic field coupling, thereby preventing spurious signal generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the control circuit and switches are disposed on the same surface of the module board, then the device complexity is reduced and ease of manufacture is improved, but spurious signals are generated in adjacent channels causing deterioration of transmission signal quality
Solution Approach 1:
The patent applies dimensionality change by moving the control circuit and switches from the same surface to opposite surfaces of the module board. This spatial separation in the third dimension (depth/thickness of the board) effectively reduces electromagnetic coupling between the control circuit and transmission path, thereby suppressing spurious signal generation in adjacent channels while maintaining a compact overall structure.
2Object-affected harmful factors
If the control circuit and switches are disposed on opposite surfaces of the module board, then spurious signal generation is suppressed and transmission signal quality is improved, but the device complexity increases
Solution Approach 1:
The patent utilizes the thickness dimension of the module board to separate the control circuit and switches onto opposite surfaces. This approach manages electromagnetic interference without significantly increasing overall device complexity, as the separation is achieved within the existing board structure rather than adding external shielding or complex routing.
3Object-affected harmful factors
If the control circuit and switches are disposed on opposite surfaces of the module board, then electromagnetic coupling is reduced and ACLR is improved, but the area of the module board increases
Solution Approach 1:
The patent reduces electromagnetic coupling by exploiting the vertical dimension (opposite surfaces of the board) rather than increasing horizontal separation. This allows the control circuit and switches to be positioned far apart in the electromagnetic sense (separated by the board thickness and grounded intermediate layer) while maintaining a compact footprint on each surface.
Solution Approach 2:
The patent introduces an intermediate grounded layer or shielding structure between the control circuit and switches on opposite surfaces. This intermediary element acts as an electromagnetic barrier, further reducing coupling effects and allowing closer positioning of components without compromising signal quality, thereby minimizing the required board area.
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 effectively prevents spurious signal generation, improving the ACLR and overall transmission signal quality by reducing coupling between the control circuit and transmission-related components.
Implementation Method 1
the control circuit is disposed on the first principal surface, and the first switch is disposed on the second principal surface... to suppress electric field, magnetic field, or electromagnetic field coupling
Implementation Method 2
the control circuit is disposed on the first principal surface, and the first switch is disposed on the second principal surface... to suppress electric field, magnetic field, or electromagnetic field coupling
Implementation Method 3
the control circuit is disposed on the first principal surface, and the first switch is disposed on the second principal surface... to suppress electric field, magnetic field, or electromagnetic field coupling
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 thereof; a transmission power amplifier; a control circuit configured to control the transmission power amplifier; a first transmission filter and a second transmission filter; and a first switch configured to switch connection of an output terminal of the transmission power amplifier between the first transmission filter and the second transmission filter. The control circuit is disposed on the first principal surface, and the first switch is disposed on the second principal surface.