RF Switch Body Bias Network for Q Factor Preservation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional RF switching circuitry degrades the quality factor due to significant loading from separate resistor networks used for biasing, which affects both the switch device and tunable RF filter structures.
Innovation Solution
The implementation of a body switching network that uses switchable paths to bias the body contact of FETs in RF switching circuitry, eliminating the need for resistor networks and reducing loading, thereby maintaining a higher quality factor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If separate resistor networks are used to bias the gate contact and body contact of FETs, then the biasing function is achieved, but significant loading of the RF switch path occurs which degrades the quality factor
Solution Approach 1:
The patent extracts and removes the resistor networks from the biasing configuration. Instead of using separate resistor networks to bias the body contact, the invention directly connects the body contact to the control contact through a switchable path, eliminating the loading effect of resistors while maintaining the necessary biasing function.
Solution Approach 2:
The patent merges the biasing function into the existing switch structure. The body contact is connected to the control contact through the same switchable path used for signal switching, combining the biasing function with the switching function and eliminating the need for separate biasing components that would load the RF path.
2Reliability
If separate resistor networks are used for biasing gate and body contacts, then proper bias control is achieved, but the complexity of the circuit increases
Solution Approach 1:
The patent removes the separate resistor networks from the circuit, simplifying the overall structure. The body contact biasing is extracted from the traditional resistor-based approach and integrated into the switchable path configuration, reducing the number of components and circuit complexity.
Solution Approach 2:
The switchable path serves multiple functions: it acts as the RF signal path when closed and simultaneously provides the bias connection for the body contact. This multi-functionality eliminates the need for separate biasing components, reducing circuit complexity while maintaining proper bias control.
Data Source
AI summary
Embodiments of radio frequency (RF) switching circuitry are disclosed that include (at least) a first switch and a body switching network operably associated with the first switch. The first switch has a first control contact, a first switch contact and a first body contact. The body switching network includes a first switchable path and a second switchable path. The first switchable path is connected between the first body contact and the first control contact of the first switch. Additionally, the second switchable path is connected between the first body contact and the first switch contact. Accordingly, the first body contact is can be appropriately biased by the switchable paths without requiring a resistor network and thus there is less loading. This maintains the Q factor of the RF switching circuitry.