Switching Voltage Regulator Frequency Selection for RF Interference
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Solution Overview
Problem
Switching voltage regulators in wireless communication devices cause interference with RF transceiver circuits due to voltage ripple, affecting device performance, especially under conditions of weak receive signal strength, external jammers, and transmit leakage, and existing solutions introduce design complexity or inefficient use of circuit space.
Innovation Solution
A method to regulate the output voltage of switching voltage regulators by adjusting the switcher frequency based on operating conditions, such as mode, frequency band, and jammer detection, using a programmable clock divider and switching voltage regulator controller to minimize interference by setting the switcher frequency higher than half the RF channel bandwidth and avoiding harmonic frequencies that could mix with transmit and receive signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If switching voltage regulator operates at fixed frequency, then power conversion efficiency is maintained, but interference with RF transceiver circuits occurs due to voltage ripple and harmonic spurious content
Solution Approach 1:
The patent applies dynamics by making the switching frequency variable rather than fixed. The controller adjusts the switching frequency based on operating conditions (transmit/receive modes, frequency bands, jammer presence) to dynamically avoid interference with RF transceiver circuits while maintaining power conversion efficiency. This is achieved through a programmable clock divider that can change the clock frequency supplied to the switching voltage regulator.
Solution Approach 2:
The patent changes the frequency parameter of the switching voltage regulator based on different operating conditions. By adjusting the switching frequency parameter, the system avoids fixed frequency harmonics that could interfere with RF transceiver circuits. The controller modifies the frequency parameter in response to transmit/receive modes, frequency bands, and detected jammer conditions.
2Object-affected harmful factors
If switching voltage regulator frequency is increased to reduce interference, then harmonic spurious content moves away from RF signals, but output voltage ripple requirements become more difficult to meet
Solution Approach 1:
The system dynamically adjusts the switching frequency to balance two competing requirements: moving harmonic spurious content away from RF signal frequencies to reduce interference, and maintaining frequency values that satisfy output voltage ripple specifications. The controller selects optimal frequency values based on real-time operating conditions.
Solution Approach 2:
The system uses feedback from the operating conditions (transmit/receive mode detection, frequency band identification, jammer presence) to adjust the switching frequency. This feedback mechanism allows the controller to select frequency values that simultaneously reduce interference and maintain voltage ripple within acceptable limits.
3Object-affected harmful factors
If multiple frequency selection options are implemented to avoid interference, then RF transceiver performance improves, but device complexity increases
Solution Approach 1:
The programmable clock divider serves multiple functions: it generates the switching frequency for the voltage regulator, allows frequency adjustment based on operating conditions, and integrates with the existing control architecture. This multi-functionality reduces the need for separate frequency selection circuits for each operating mode.
Solution Approach 2:
The controller automatically selects appropriate switching frequencies based on detected operating conditions without requiring external intervention or complex manual configuration. The system self-adjusts the frequency in response to transmit/receive modes, frequency bands, and jammer detection, reducing the burden on the designer and user.
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 effectively reduces interference from switching voltage regulators, improving the performance of wireless communication devices by minimizing spurious content and jamming effects on RF VCO outputs and receive signals, while maintaining efficient power conversion.
Implementation Method 1
Switching voltage regulators may convert between a higher input voltage and a lower output voltage using one or more electronic switches in conjunction with energy storage devices (inductors or capacitors) to transfer energy
Implementation Method 2
energy storage devices (inductors or capacitors) to transfer energy between a higher external DC power supply voltage and a lower integrated circuit voltage
Implementation Method 3
energy storage devices (inductors or capacitors) to transfer energy
Data Source
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AI summary
Techniques for mitigating interference from a switching voltage regulator by intelligently varying the switcher frequency of the switching voltage regulator are provided. In one aspect, the switcher frequency is set by adjusting a frequency setting input to variable clock frequency generating circuit. The frequency setting is representative of at least a current operating mode condition. The output voltage is regulated by a switching voltage regulator controller in response to the switcher frequency and a reference voltage.