RF Module PCB Layout to Suppress ACLR Spurious Coupling
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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 a power amplifying module is used as a transmission circuit.
Innovation Solution
A radio frequency module configuration where the control circuit and first inductor are disposed on opposite surfaces of a module board, effectively suppressing electric field, magnetic field, or electromagnetic field coupling, thereby preventing spurious signal generation and improving ACLR.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the control circuit and first inductor 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 from the same surface to the opposite surface of the module board, separating it spatially from the first inductor in the vertical dimension. This physical separation prevents electromagnetic coupling between the digital control signal lines and the RF signal path through the inductor, thereby eliminating spurious signal generation in adjacent channels while maintaining manufacturing feasibility through standard dual-sided PCB technology.
2Object-affected harmful factors
If the control circuit is separated from the first inductor by placing them on opposite surfaces of the module board, then transmission signal quality is improved by suppressing spurious signals, but the device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the module board into distinct functional zones: the first surface houses RF components including the first inductor and transmission power amplifier, while the second surface houses the control circuit. This segmentation creates clear electrical and electromagnetic boundaries between RF signal paths and digital control signals, preventing interference without requiring complex shielding or filtering circuits, thus managing device complexity through systematic layout rather than additional components.
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 enhances transmission signal quality by preventing digital control signal-induced spurious signals, thus improving the ACLR and overall signal transmission performance.
Implementation Method 1
the control circuit and first inductor are disposed on opposite surfaces of a module board, effectively suppressing electric field, magnetic field, or electromagnetic field coupling
Implementation Method 2
the control circuit and first inductor are disposed on opposite surfaces of a module board, effectively suppressing electric field, magnetic field, or electromagnetic field coupling
Implementation Method 3
the control circuit and first inductor are disposed on opposite surfaces of a module board, effectively suppressing 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 that controls the transmission power amplifier, and a first inductor connected to an output terminal of the transmission power amplifier. The control circuit is disposed on the first principal surface, and the first inductor is disposed on the second principal surface.