Stacked RF Switch Circuit for Uniform Voltage Swing Distribution
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Solution Overview
Problem
Existing RF switching circuits face challenges in achieving high average power withstanding capability and low insertion loss, particularly due to uneven voltage distribution and nonlinear phenomena in stacked transistor chains.
Innovation Solution
The RF switching circuit employs a series-connected configuration of switch transistor units, each comprising a first and second transistor, bias resistors, and a path resistor, with specific connections to improve voltage distribution and reduce nonlinearity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a stacked chain of switch transistors is used to increase power withstanding capability, then the average power withstanding capability is improved, but the voltage swing becomes unevenly distributed and nonlinearity increases
Solution Approach 1:
The patent introduces a bulk connection network as an intermediary component between the stacked switch transistors. This network includes bulk connection resistors that connect corresponding bulks of adjacent transistors, acting as a mediator to redistribute voltage swings evenly across the transistor stack and reduce nonlinearity while maintaining high power withstanding capability
Solution Approach 2:
The patent modifies the electrical parameters of the transistor stack by adding bulk connection resistors with specific resistance values. This changes the voltage distribution parameters across the stacked transistors, transforming the uneven voltage swing distribution into a more uniform distribution that reduces nonlinearity
2Power
If more switch transistors are stacked in series to increase power handling, then the power withstanding capability is improved, but the insertion loss increases
Solution Approach 1:
The bulk connection network serves as an intermediary that reduces the effective on-resistance of the transistor stack by providing alternative current paths through the bulk connections. This reduces insertion loss while maintaining the high power withstanding capability provided by the stacked configuration
Data Source
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AI summary
A radio frequency switching circuit which has high tolerance power, a chip and an electronic device thereof. The radio frequency switching circuit is composed of multiple stages of switching transistor units connected in series. In each stage of switching transistor units, a body electrode of a first transistor (M1, M2, ..., Mn) is connected to a source and a body electrode of a second transistor (M1a, M2b, M3a, ..., Mi-1a, Mib, Mia, ..., Mnb); a drain of the first transistor (M2, M3, ..., Mn) is connected to an output terminal of a previous-stage switching transistor unit (M1, M2, ..., Mn-1); on the one hand, a source of the first transistor (M1, M2, ..., Mn) is connected to a gate of the second transistor (M1a, M2b, M3a, ..., Mi-1a, Mib, Mia, ..., Mnb), and on the other hand, the source of the first transistor (M1, M2, ..., Mn) is connected to the drain of a first transistor (M2, M3, ..., Mn) in a subsequent-stage switching transistor unit; and a path resistor (Rds1, Rds2, ..., Rdsn) is provided between the drain and the source of the first transistor (M1, M2, ..., Mn). According to the radio frequency switching circuit, the phenomenon of uneven distribution of a voltage swing in stages of a switching transistor stacking chain is improved, so that the problem of nonlinearity of the radio frequency switching circuit is improved, the insertion loss is reduced, and the average tolerance power is significantly improved.