PLL Oscillator Frequency Correction Under Power Amplifier Interference
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Solution Overview
Problem
Existing radio signal processing devices face challenges in suppressing oscillation frequency variations caused by interference from power amplifiers, leading to phase locked loop unlocking, which hinders integration of power amplifiers and matching circuits into a single chip, resulting in increased chip size and power consumption.
Innovation Solution
A radio signal processing device equipped with a variation detection unit to monitor control signal changes and a variation correction unit to generate a second control signal, adjusting the oscillator's frequency to counteract interference-induced variations, thereby maintaining lock operation and allowing for integration of power amplifiers and matching circuits on the same chip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If power amplifier and matching circuit are integrated on a single chip, then chip size and power consumption are reduced, but oscillation frequency variation increases causing phase locked loop unlocking
Solution Approach 1:
The patent applies preliminary anti-action by detecting the variation direction of the control signal before the phase locked loop unlocks, and generating a correction signal in advance to counteract the harmful frequency variation. The variation detection unit monitors control signal changes and the variation correction unit generates compensation signals proactively, preventing the unlocking condition rather than reacting after it occurs.
Solution Approach 2:
The patent implements feedback by using the variation detection unit to continuously monitor control signal variations and feed this information back to the variation correction unit. This closed-loop feedback mechanism allows the system to dynamically adjust the correction signal based on real-time variations, maintaining phase locked loop lock operation despite integration-induced interference.
2Productivity
If power amplifier is turned on, then radio transmission function is enabled, but oscillation frequency varies due to input impedance change
Solution Approach 1:
The patent applies the counterweight principle by generating a correction signal that opposes and cancels out the frequency variation caused by power amplifier operation. The variation correction unit produces a control signal with equal magnitude but opposite polarity to the detected variation, effectively neutralizing the harmful effect and maintaining stable oscillation frequency during radio transmission.
3Device complexity
If fixed correction amount is used, then implementation is simple, but oscillation frequency variation cannot be suppressed in all cases
Solution Approach 1:
The patent implements dynamics by transitioning from a fixed correction approach to a dynamic, adaptive correction mechanism. The variation detection unit continuously monitors control signal variations, and the variation correction unit dynamically adjusts the correction signal magnitude and polarity based on real-time conditions. This dynamic adaptation ensures effective frequency variation suppression across different operating scenarios while maintaining reasonable system complexity.
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 suppresses oscillation frequency variations, preventing phase locked loop unlocking and enabling the integration of power amplifiers and matching circuits on a single chip, reducing chip size and power consumption while maintaining signal quality.
Implementation Method 1
a phase locked loop that controls the oscillator by generating the first control signal to be output to the oscillator
Implementation Method 2
a power amplifier that amplifies a radio transmission signal on the basis of the oscillation signal
Implementation Method 3
a variation detection unit that detects the variation of a first control signal output by a phase locked loop to an oscillator
Implementation Method 4
a variation correction unit that generates a second control signal on the basis of the detected variation to correct the variation of the oscillation frequency
Data Source
AI summary
The variation of the oscillation frequency of an oscillator can be suppressed even in the case where the amount of interference with the oscillator accompanied by an amplifying operation of a power amplifier and the polarity are not constant. An oscillator is configured to be capable of oscillating at an oscillation frequency in accordance with control signals Vcont and FREQ_CTRL. A phase locked loop allows the oscillator to output an oscillation signal Vout in synchronization with a reference signal RELCLK using the control signal Vcont. A power amplifier amplifies the electric power of the oscillation signal Vout. A variation detection unit detects a variation with respect to the time change of the control signal Vcont after an amplifying operation is started by the power amplifier causing 3interference with the oscillator. A variation correction unit generates the control signal FREQ_CTRL on the basis of the variation detected by the variation detection unit, and corrects the variation of the oscillation frequency caused by the interference accompanied by the amplifying operation of the power amplifier.