Charge Pump RF Protection Switch for Receiver Voltage Swings
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Solution Overview
Problem
RF transmitters transmit high power levels that can cause voltage swings, leading to reduced lifetime and performance of sensitive circuit components in victim devices due to lack of protection between antennas and integrated circuit components.
Innovation Solution
Implementing a charge pump and transistor feedback loop at the receiver input to shunt excess power to ground, using a charge pump to convert incoming power to DC voltage and control a transistor as a shunt switch, thereby protecting sensitive circuit components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a charge pump and transistor feedback loop is implemented to shunt excess power, then sensitive circuit components are protected from voltage swings, but device complexity increases
Solution Approach 1:
The protection circuit uses the harmful high-power signal itself to activate the protection mechanism. The charge pump converts the incoming RF power to DC voltage, which automatically turns on the transistor switch when voltage thresholds are exceeded, eliminating the need for external control circuits or additional power sources.
Solution Approach 2:
The circuit implements a feedback mechanism where the charge pump continuously monitors the voltage at its input node and adjusts the transistor gate voltage accordingly. When the input voltage exceeds the threshold, the charge pump generates DC voltage that turns on the transistor, which then shunts the excess power, creating a closed-loop protection system.
2Reliability
If diodes are used to shunt large amounts of power, then circuit protection is provided, but excess capacitance degrades circuit performance
Solution Approach 1:
The invention replaces traditional diode protection with a transistor-based switch that can handle high power levels. The transistor acts as a controllable switch that can shunt power only when needed, rather than being permanently conductive like a diode, thereby reducing continuous capacitance effects on the RF circuit.
Solution Approach 2:
The circuit dynamically changes the electrical parameters of the protection element. The transistor's resistance changes from high (off state) to low (on state) based on the input power level, allowing it to adapt its protection level rather than maintaining fixed characteristics like a diode would.
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
The solution effectively protects sensitive circuit components by shunting excess power, reducing voltage swings and maintaining performance without degrading circuit performance with excess capacitance.
Implementation Method 1
using a charge pump to convert incoming power to DC voltage
Implementation Method 2
control a transistor as a shunt switch, thereby protecting sensitive circuit components
Data Source
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AI summary
Radio frequency (RF) transmitters of a device (aggressor device) may unintentionally transmit a high-power output signal to antennas of a receiving device (victim device). In some RF systems, a victim device may have no or little protection between its antennas and transistors in an integrated circuit. Performance or lifetime of the transistors may be negatively impacted due to large voltage swings that may result from the high-power signal received from the aggressor device. To prevent or mitigate impact to performance or lifetime of the transistors due to the large voltage swings, protection circuitry including switches and a direct current (DC) power source (e.g., a charge pump) may be implemented at an input of a receiver of the victim device to shunt the power from sensitive circuit components of the victim device.