RF Switch FET Body Biasing With Diode Stacks Against GIDL
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Solution Overview
Problem
In RF switch stacks, gate-induced drain/body leakage current (GIDL) causes undesired de-biasing effects, leading to early transistor breakdown and increased complexity in bias generator design, requiring more area and power consumption.
Innovation Solution
The implementation of diode stacks across the body resistor ladder in RF switch stacks to create multiple current discharge paths during different RF signal swings, mitigating GIDL current and maintaining proper voltage distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If body resistor ladder is used to bias RF switch stack, then voltage distribution is provided to transistors, but GIDL current causes de-biasing effect leading to early transistor breakdown
Solution Approach 1:
Diode stacks are introduced as intermediary elements connected between body resistor ladder nodes and RF signal terminals. These diode stacks act as mediators that provide alternative current paths for GIDL current, preventing it from flowing through the body resistor ladder and causing de-biasing effects, thereby protecting transistors from early breakdown
Solution Approach 2:
The body resistor ladder is segmented by introducing diode stacks at intermediate nodes. Each diode stack creates a separate current discharge path, effectively dividing the single biasing network into multiple independent segments that can handle GIDL current locally without affecting the overall voltage distribution
2Stability of the object's composition
If GIDL current is sunk by biasing circuits, then voltage distribution is maintained, but bias generator complexity and area increase
Solution Approach 1:
The diode stacks enable the body resistor ladder to self-manage GIDL current by providing local discharge paths. Instead of requiring the bias generator to actively sink GIDL current, the structure itself becomes self-sufficient by routing leakage current through diode stacks to appropriate nodes, maintaining voltage distribution without increasing bias generator complexity
3Ease of operation
If more negative biasing voltage is applied to improve linearity, then linearity performance improves, but biasing circuit area and power consumption increase
Solution Approach 1:
The diode stacks convert the harmful GIDL current into a beneficial mechanism for maintaining voltage distribution. By providing controlled paths for leakage current, the system can achieve improved linearity performance through proper biasing without requiring excessively negative voltages, thus reducing the area and power consumption of the biasing circuit
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 approach reduces the negative impacts of GIDL current, preventing early transistor breakdown, simplifying the biasing circuit, and maintaining power handling and linearity performance while reducing DC current consumption.
Implementation Method 1
a diode element stack comprising two or more diode elements, the diode element stack coupled between the body resistor ladder and the first terminal
Implementation Method 2
a body resistor ladder coupled to the first terminal, the body resistor ladder comprising a plurality of body resistor elements connected in series
Data Source
AI summary
Methods and devices to reduce gate induced drain leakage current in RF switch stacks are disclosed. The described devices utilize multiple discharge paths and/or less negative body bias voltages without compromising non-linear performance and power handling capability of power switches. Moreover, more compact bias voltage generation circuits with smaller footprint can be implemented as part of the disclosed devices.