Crystal-Free RF Oscillator Calibration Using Periodic Wireless Packets
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless devices rely on external crystal or MEMS resonators for timekeeping, which increases cost and power consumption, limiting their scalability and functionality in dynamic wireless networks, especially for battery-less IoT applications.
Innovation Solution
A crystal-free wireless system using a Frequency Locked Loop (FLL) with a relaxation oscillator or RF Local Oscillator that calibrates an on-chip clock reference through periodic RF packets, eliminating the need for external resonators and enabling low-power, low-cost operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If external crystal or MEMS resonators are used for timekeeping, then timing accuracy is improved, but cost and power consumption increase
Solution Approach 1:
The patent removes the external crystal or MEMS resonator from the wireless device, extracting the high-power timekeeping component from the system. Instead, it uses a low-power relaxation oscillator on-chip that is calibrated periodically using RF packets from the wireless network, thereby eliminating the need for expensive and power-hungry external resonators while maintaining timing accuracy.
Solution Approach 2:
The patent introduces RF packets from the wireless network as an intermediary mechanism for time calibration. These periodic RF packets serve as an external time reference that calibrates the on-chip relaxation oscillator without requiring a dedicated external resonator, thus achieving accurate timing through a mediating communication signal rather than a direct hardware connection.
2Measurement precision
If external crystal or MEMS resonators are used for timekeeping, then timing accuracy is improved, but device cost increases
Solution Approach 1:
The patent removes the external crystal or MEMS resonator from the wireless device, extracting the high-cost timekeeping component from the system. Instead, it uses a low-cost on-chip relaxation oscillator that is calibrated periodically using RF packets from the wireless network, thereby eliminating the need for expensive external resonators while maintaining timing accuracy.
Solution Approach 2:
The patent merges the timekeeping function with the existing wireless communication infrastructure. The same RF communication channel used for data transmission also serves as the calibration source for timing, eliminating the need for separate expensive timekeeping hardware and reducing overall device cost.
3Use of energy by moving object
If crystal-free oscillators are used, then power consumption and cost are reduced, but timing accuracy and jitter performance deteriorate
Solution Approach 1:
The patent implements a feedback mechanism where periodic RF packets from the wireless network provide time reference information that is used to校准 the on-chip relaxation oscillator. This feedback loop continuously corrects drift in the low-power oscillator, maintaining timing accuracy without requiring a high-power crystal resonator.
Solution Approach 2:
The patent uses periodic RF packets transmitted over the wireless network to perform intermittent calibration of the on-chip oscillator. Instead of continuously running a high-power crystal resonator, the system performs calibration at periodic intervals using the available wireless communication infrastructure, achieving accurate timing with reduced average power consumption.
4Use of energy by moving object
If crystal-free oscillators are used, then power consumption and cost are reduced, but jitter performance deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where periodic RF packets from the wireless network provide time reference information that is used to校准 the on-chip relaxation oscillator. This feedback loop continuously corrects drift in the low-power oscillator, maintaining timing accuracy without requiring a high-power crystal resonator.
Solution Approach 2:
The patent introduces RF packets from the wireless network as an intermediary mechanism for time calibration. These periodic RF packets serve as an external time reference that calibrates the on-chip relaxation oscillator without requiring a dedicated external resonator, thus achieving accurate timing through a mediating communication signal rather than a direct hardware connection.
Data Source
AI summary
A crystal-free wireless device includes a frequency calibration module and a local radio frequency (RF) oscillator having a first frequency and configured to communicate with the frequency calibration module. The crystal-free wireless device also includes a relaxation ring oscillator configured to communicate with the frequency calibration module. The relaxation ring oscillator is further configured to receive a calibration signal or periodic radio frequency packets from a wireless network and provide a reference signal to the frequency calibration module. The relaxation ring oscillator is a crystal-free oscillator. The frequency calibration module is configured to generate a calibration signal that is fed back through a Frequency Locked Loop (FLL) to the local RF oscillator to calibrate the local RF oscillator. The calibrated local RF oscillator is configured to generate a clock signal.