RF Switch Ballasting Capacitance for Bidirectional Voltage Equalization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Radio frequency (RF) switch devices experience unequal voltage drops across switches due to parasitic capacitance and high peak voltages, leading to unwanted conductive paths and voltage inequalities, which existing solutions fail to adequately address, especially in applications where the high-voltage terminal is not predetermined.
Innovation Solution
The RF switch device incorporates a series of switch units with ballasting capacitor units that provide selectable capacitance values, allowing for adaptive capacitance adjustment along the signal path to equalize voltage drops, using a combination of permanent and selectable capacitor elements and switchable capacitance selection lines to manage capacitance values between 1 fF and 100 fF, and detect peak voltages or leakage currents to optimize capacitance settings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If capacitors with high capacitance are connected in parallel to switches closer to the high-voltage terminal, then voltage drops are equalized for that specific direction, but the solution becomes invalid and increases inequalities when the voltage direction is reversed
Solution Approach 1:
The patent applies dynamics by making the capacitance values selectable and reconfigurable rather than fixed. Each ballasting capacitor unit can switch between a first capacitance value and a second capacitance value based on the operating direction, allowing the system to adapt dynamically to different voltage polarity conditions and maintain voltage drop equalization in both directions
Solution Approach 2:
The patent changes the parameter of capacitance from fixed to variable by implementing selectable capacitance values. The ballasting capacitor units can change their capacitance parameter between a first value and a second value depending on which terminal is at high voltage, thereby maintaining effective voltage equalization regardless of voltage direction
2Device complexity
If fixed capacitance values are used in ballasting capacitor units, then the device structure is simplified, but the device cannot adapt to different voltage directions and loses reliability in bidirectional applications
Solution Approach 1:
The patent introduces dynamic control by implementing selectable capacitance values in each ballasting capacitor unit. The capacitance can be changed based on operational requirements and voltage direction, transforming a static structure into a dynamic system that adapts to different operating conditions while maintaining reliability
Solution Approach 2:
The patent achieves universality by designing ballasting capacitor units that can serve multiple functions through selectable capacitance values. The same hardware configuration can handle both directional applications by switching between first and second capacitance values, making the device universally applicable regardless of voltage polarity
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 solution effectively equalizes voltage distribution across switch units within a tolerance of ±20% across the RF switch device, ensuring uniform operation under varying peak voltage conditions and allowing the same hardware to be used in different directional applications, thereby improving the reliability and adaptability of RF switch devices.
Implementation Method 1
each ballasting capacitor unit comprises at least one ballasting capacitor switch element configured to switch the capacitance of the ballasting capacitor unit between: a first capacitance value; and a second capacitance value
Data Source
AI summary
A radio frequency, RF, switch device includes a plurality of switch units, wherein the switch units are coupled in series between a first series terminal and a second series terminal to establish a switchable RF path; and a plurality of ballasting capacitor units, wherein each ballasting capacitor unit is coupled in parallel to a respective switch unit, to provide a selectable capacitance in parallel to a signal path of the respective switch unit, wherein each ballasting capacitor unit includes at least one ballasting capacitor switch element to switch the capacitance of the ballasting capacitor unit between a first capacitance value and a second capacitance value, wherein the second capacitance value is larger than the first capacitance value.