RF Transmitter Phase Shifting for Oscillator Pulling Reduction
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Solution Overview
Problem
RF transmitters experience performance deterioration due to pushing and pulling effects, which are not efficiently addressed by existing technologies, leading to issues such as Error Vector Magnitude (EVM) and spectral regrowth.
Innovation Solution
Incorporating a phase shifter module between the phase-locked loop and the power amplifier to introduce a phase shift between the oscillator carrier and the power amplifier's harmonic, reducing frequency shifts caused by pushing and pulling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the power amplifier power is increased, then the transmitted signal strength is improved, but the oscillator frequency shifts away from the wanted value due to pushing and pulling effects
Solution Approach 1:
A phase shifter module is introduced as an intermediary component between the oscillator and power amplifier. This phase shifter adjusts the phase of the oscillator signal before it reaches the power amplifier, thereby controlling the interaction between the oscillator carrier and power amplifier harmonic to minimize frequency pulling while maintaining transmitted signal strength.
Solution Approach 2:
The invention changes the phase parameter of the oscillator signal dynamically. By adjusting the phase shift introduced by the phase shifter module, the system optimizes the interaction between oscillator and power amplifier to reduce frequency deviation while preserving output power levels.
2Power
If the power amplifier power is increased, then the transmitted signal strength is improved, but the modulation quality deteriorates in terms of Error Vector Magnitude and spectral regrowth
Solution Approach 1:
The phase shifter module serves as a mediator that optimizes the phase relationship between the oscillator carrier and power amplifier output. This controlled phase adjustment reduces spectral regrowth and improves Error Vector Magnitude by minimizing nonlinear distortion effects in the power amplifier.
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 phase shifter module effectively minimizes frequency shifts, improving modulation quality metrics like EVM and reducing spectral regrowth in RF transmitters.
Implementation Method 1
a phase shifter module between the phase-locked loop and the power amplifier, arranged to introduce a phase shift between the oscillator carrier and a harmonic of the power amplifier current
Data Source
AI summary
A RF transmitter includes a phase-locked loop having an oscillator arranged to output an oscillator carrier and a power amplifier arranged to conduct a power amplifier current. The RF transmitter includes a phase shifter module between the phase-locked loop and the power amplifier arranged to introduce a phase shift between the oscillator carrier and a harmonic of the power amplifier current in order reduce a frequency shift of the oscillator carrier due to pushing and/or pulling.