RF Transmitter Compensation Circuit Impedance Mismatch
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Solution Overview
Problem
The complex circuit structure of current source sets in radio frequency transmitters leads to parasitic effects, resulting in low efficiency and limited performance improvement, especially when operating in millimeter wave bands.
Innovation Solution
A compensation circuit is introduced in the radio frequency transmitter's front-end to address the impedance mismatch between current source subsets by compensating for the difference in load impedance, thereby improving the overall efficiency of the transmitter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a current source set with complex circuit structure is used to generate RF output signal, then the radio frequency transmitter can achieve signal generation capability, but parasitic effect becomes obvious in millimeter wave band leading to low efficiency
Solution Approach 1:
The current source set is divided into N current source subsets, where each subset contains multiple current source units. This segmentation allows for independent impedance compensation for each subset, reducing the overall parasitic effect while maintaining signal generation capability. The segmented structure enables targeted optimization of each subset's load impedance without affecting the entire current source set.
2Power
If current source set with complex circuit structure is used, then signal generation is achieved, but impedance mismatch occurs between current source subsets increasing power loss
Solution Approach 1:
Each current source subset is equipped with an independent compensation circuit that locally compensates for the load impedance difference specific to that subset. This local quality approach ensures that each subset operates with optimized impedance matching, reducing power loss while maintaining overall signal generation capability. The local compensation is more effective than global compensation because it addresses the specific parasitic characteristics of each subset.
3Power
If complex circuit structure of current source set is used, then RF signal generation is enabled, but device complexity increases limiting performance improvement
Solution Approach 1:
The compensation circuits adjust the load impedance parameters of each current source subset to achieve optimal matching. By changing the impedance parameters dynamically or through design optimization, the system maintains high efficiency without requiring overly complex circuit topologies. The parameter adjustment approach is simpler than redesigning the entire circuit structure.
Data Source
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AI summary
A radio frequency transmitter is provided. The radio frequency transmitter mainly includes a radio frequency front-end and a control circuit. The radio frequency front-end includes a current source set, a compensation circuit, and a matching network. The compensation circuit may compensate for a difference of load impedance between N current source subsets in the current source set. Therefore, an impedance mismatch of the current source set may be improved, and a power loss of the current source set may be reduced. This helps improve efficiency of the radio frequency transmitter.