RF Control Circuit Harmonic Interference Suppression
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Solution Overview
Problem
In existing carrier-aggregated RF circuits, harmonics from the primary component carrier (PCC) signal interfere with the reception of secondary component carrier (SCC) signals, leading to poor reception quality and stability issues in mobile terminals due to shared power amplifiers.
Innovation Solution
The RF control circuit employs a working-mode-switching switch to ground the transmission sub-path of the SCC path, preventing harmonic interference from the PCC signal, thus ensuring that the SCC signal is not affected during transmission and reception operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple frequency band carriers share one power amplifier to increase transmission bandwidth, then carrier aggregation capability is improved, but harmonic interference occurs between PCC and SCC signals
Solution Approach 1:
The patent segments the signal transmission path by introducing a dedicated harmonics filtering path that separates the PCC signal processing from the SCC signal reception path. This segmentation prevents the harmonics generated by the power amplifier from interfering with the SCC signal, while still allowing both carriers to share the same power amplifier for bandwidth aggregation.
Solution Approach 2:
The patent introduces an intermediary filtering mechanism (harmonics filtering path) between the power amplifier output and the SCC signal reception path. This intermediary component selectively removes harmful harmonics while allowing the desired SCC signal to pass through, resolving the interference issue without sacrificing carrier aggregation capability.
2Device complexity
If a multi-mode multi-frequency power amplifier is used to aggregate carriers, then device complexity is reduced, but reception quality of SCC signals deteriorates due to harmonic interference
Solution Approach 1:
The patent introduces an intermediary filtering mechanism (harmonics filtering path) between the power amplifier output and the SCC signal reception path. This intermediary component selectively removes harmful harmonics while allowing the desired SCC signal to pass through, resolving the interference issue without sacrificing carrier aggregation capability.
Solution Approach 2:
The patent changes the frequency parameter selection by designing the harmonics filtering path to specifically target and remove harmonic frequencies (e.g., 2nd harmonic at 2*f_PCC, 3rd harmonic at 3*f_PCC) while preserving the fundamental SCC signal frequency. This selective frequency parameter manipulation maintains reception quality while keeping the power amplifier structure simple.
3Object-affected harmful factors
If the transmission sub-path of SCC path is grounded during PCC transmission, then harmonic interference is eliminated, but signal transmission capability is reduced
Solution Approach 1:
The patent implements a dynamic switching mechanism that controls the grounding state of the transmission sub-path based on the operational mode. When PCC transmission is active, the transmission sub-path is grounded to block harmonics; when SCC transmission is needed, the grounding is removed to restore signal transmission capability. This dynamic adjustment resolves the contradiction between interference elimination and transmission capability.
Solution Approach 2:
The patent applies preliminary anti-action by proactively grounding the transmission sub-path before harmonic interference can occur during PCC transmission. This preventive measure blocks the interference path in advance, and the system dynamically restores the path when needed for SCC transmission, thus preventing harm while preserving capability.
Data Source
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AI summary
Provided is a radio frequency control circuit, comprising a transceiver module, a front-end module and a working mode switching switch; the transceiver module is used to send a primary carrier signal of a local data signal and receive a main carrier signal of an external data signal by means of a main carrier path, and is used to send a secondary carrier signal of the local data signal and receive a secondary carrier signal of the external data signal by means of a secondary carrier path; the front-end module is used to receive the external data signal and transmit the local data signal; the working mode switching switch comprises a switch control terminal connected to the transceiver module, a switch input terminal connected to a transmission sub-path of the secondary carrier path and a grounded switch output terminal. Further provided in the present invention is a mobile terminal.