Injection-Locked Clock Supply for Low-Power Frequency Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In low-power wireless communications, frequency synthesizers like PLLs or VCOs consume a majority of the power, posing challenges in battery size and charge limitations for devices such as wireless sensor nodes and telemetry systems.
Innovation Solution
A clock frequency supply device that includes a frequency tuner, an injector, and an oscillator, where the frequency tuner deactivates after tuning, and the injector controls the input signal to maintain the oscillation frequency locked to the carrier frequency, reducing power consumption by using a gate to restrict the carrier frequency supply and employing injection locking with a signal magnitude adjuster and ON/OFF switch.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a frequency synthesizer (PLL or VCO) is used to generate clock frequency, then accurate frequency generation is achieved, but power consumption increases significantly
Solution Approach 1:
The frequency tuner performs preliminary frequency adjustment before injection locking occurs. By pre-tuning the oscillator frequency to match the carrier frequency, the system reduces the time and power needed for frequency acquisition, while maintaining accurate frequency generation through the subsequent injection locking mechanism.
Solution Approach 2:
The oscillator uses the injected carrier signal itself to lock its frequency, rather than requiring continuous active control from the frequency synthesizer. Once the frequency tuner prepares the oscillator and the injector introduces the carrier signal, the oscillator self-adjusts to lock onto the carrier frequency, significantly reducing power consumption while maintaining frequency accuracy.
2Measurement precision
If continuous frequency tuning is performed to maintain frequency locking, then frequency accuracy is maintained, but power consumption and calibration time increase
Solution Approach 1:
The system uses periodic injection of the carrier signal through the injector to maintain frequency locking, rather than continuous frequency tuning. The frequency tuner performs initial adjustment, then the periodic injection of carrier signals keeps the oscillator locked without requiring continuous active tuning, reducing both calibration time and power consumption.
Solution Approach 2:
The injection locking mechanism provides automatic feedback where the oscillator's output is compared with the injected carrier signal, and the phase and frequency difference automatically adjust the oscillator to maintain locking. This self-correcting feedback mechanism maintains frequency accuracy without requiring external continuous control signals.
3Measurement precision
If the frequency tuner remains active to maintain frequency locking, then frequency accuracy is maintained, but power consumption increases
Solution Approach 1:
The active frequency tuning function is extracted from the continuous operation mode and replaced with injection locking. The frequency tuner is only activated when needed for initial frequency adjustment, then its function is taken over by the passive injection locking mechanism that uses the carrier signal itself to maintain frequency accuracy without requiring the frequency tuner to remain active.
Solution Approach 2:
The oscillator maintains frequency locking through self-service injection locking, where the injected carrier signal automatically keeps the oscillator synchronized without requiring continuous active control from the frequency tuner. This self-maintaining mechanism preserves frequency accuracy while eliminating the need for continuous frequency tuner operation.
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 reduces overall power consumption, minimizes calibration time, and maintains accurate frequency locking with low power usage, suitable for communication modules like NFC, while simplifying the frequency locking process.
Implementation Method 1
an oscillation signal generator (oscillator) configured to generate an oscillation signal with an oscillation frequency
Implementation Method 2
a frequency tuner configured to tune the oscillation frequency of the oscillation signal based on the carrier frequency
Implementation Method 3
an injector configured to feed the input signal to the oscillation signal generator (oscillator) after the tuning of the oscillation frequency is completed
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A clock frequency supply device includes: a frequency tuner configured to receive an input signal with a carrier frequency, and tune an oscillation frequency of an oscillator based on the carrier frequency; an injector configured to inject the input signal directly into the oscillator after the tuning of the oscillation frequency is completed; and an oscillator configured to generate a reference clock signal with a reference clock frequency based on the injected input signal.