RF Clock Signal Derivation for GPS-Disruption Resilience

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Solution Overview

Problem

Existing systems reliant on GPS for time data are vulnerable to disruptions, leading to potential catastrophic failures in critical infrastructure and services.

Innovation Solution

A radio frequency (RF) clocked device that utilizes common terrestrial radio signals to maintain precise timing without requiring time or date information, using a signal processor to derive a clock frequency from RF signals, and includes a clock to output time and date information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If GPS signals are used for time synchronization, then accurate and reliable time data is obtained, but the system becomes vulnerable to disruptions from malicious attacks or natural events

Engineering Contradiction:
Improvetime data reliabilityVSAvoiddisruption vulnerability
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces an intermediary mechanism - a phase-locked loop (PLL) circuit - that mediates between the RF signal source and the clock system. The PLL acts as a buffer that can switch between GPS-synchronized mode and free-running mode, allowing the system to maintain timekeeping functionality even when GPS signals are disrupted, thereby reducing vulnerability while preserving reliability

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically changes its operational parameters by switching between two states: synchronized operation (when GPS is available) and free-running operation (when GPS is disrupted). The PLL circuit adjusts its locking state based on signal availability, enabling the system to adapt to varying conditions and maintain functionality across different operational scenarios

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If GPS dependency is eliminated, then system resilience against disruptions is improved, but the ability to maintain accurate timing without GPS signals becomes challenging

Engineering Contradiction:
ImproveGPS-denied environment operationVSAvoidtimekeeping accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The system performs preliminary synchronization with GPS signals when available, storing the synchronized time reference in the PLL circuit. This preliminary action ensures that when GPS signals are later disrupted, the system already has a stored reference to maintain accurate timing, thus preserving measurement precision while enabling operation in GPS-denied environments

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The RF clocked device is designed to be self-sufficient by incorporating a free-running capability through the PLL circuit. When GPS signals are unavailable, the system serves itself by maintaining timekeeping using the last synchronized reference, eliminating the need for external GPS dependency while preserving timing accuracy through internal memory and stabilization mechanisms

Inventive Principle:
Principle #25Self-service

3Adaptability or versatility

If RF signals are used instead of GPS, then independence from GPS infrastructure is achieved, but the complexity of deriving accurate time data from RF signals increases

Engineering Contradiction:
Improveterrestrial radio signal utilizationVSAvoidsignal processing complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent replaces complex software-based signal processing with a hardware-based phase-locked loop circuit. The PLL provides automatic frequency and phase tracking through analog/digital hardware mechanisms, simplifying the overall system architecture while enabling RF signal utilization. This substitution reduces processing complexity while maintaining the ability to derive accurate time data from terrestrial radio signals

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Enables continuous and accurate timekeeping in GPS-denied environments by leveraging stable RF signals, ensuring uninterrupted operation of critical systems.

Implementation Method 1

a signal processor operable to receive an RF signal having an RF signal frequency and output a clock signal having a clock frequency based on the RF signal frequency

Methodology Applied
Scientific EffectElectromagnetic signal reception and frequency derivation:

Data Source

PatentEP4100799B1Radio frequency clocked device
Publication Date: 2025.11.19 RTX BBN TECH INC
  • EP4100799B1 patent drawingFigure 1
  • EP4100799B1 patent drawingFigure 2
  • EP4100799B1 patent drawingFigure 3~4

AI summary

An RF clocked device includes a signal processor operable to receive an RF signal having an RF signal frequency and output a clock signal having a clock frequency based on the RF signal frequency. The RF clocked device includes a clock that operates using the clock signal. The clock can output at least one of a time or a date. A clock system can include an RF clocked device. The RF clocked device includes a signal processor operable to receive an RF signal having an RF signal frequency and output a clock signal having a clock frequency based on the RF signal frequency. The RF clocked device includes a clock operable to receive, and operate, using the clock signal. The clock can output at least one of a time and a date. The clock system can include a client device operable to receive timing information from the RF clocked device.