Single-Antenna Door Opening Detection by Resonant Frequency Shift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Commercially available door/window opening detectors require two elements, increasing complexity and cost, necessitating a single-element solution for detection.
Innovation Solution
A single-element door/window opening detector utilizing an antenna with distinct resonant frequencies to detect changes in proximity, employing a high-frequency oscillator, coupler, detector, and analog-to-digital converter to generate an alarm indication based on resonant frequency changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two-element detector system is used, then detection reliability is improved, but device complexity and cost increase
Solution Approach 1:
The patent combines the sensor element and magnetic element into a single integrated detector unit mounted on the door or window. This single element performs both sensing and magnetic field generation functions, eliminating the need for separate fixed sensor and movable magnetic elements, thereby reducing system complexity while maintaining detection reliability
Solution Approach 2:
The single detector element is designed to perform multiple functions: it acts as both a sensor for detecting opening/closing states and as a magnetic field source. This multi-functional design replaces the traditional two-element system where separate components performed sensing and magnetic field generation independently
2Measurement precision
If two-element detector system is used, then detection accuracy is improved, but manufacturing cost increases
Solution Approach 1:
By merging the sensor and magnetic element into one integrated component, the patent reduces the total number of parts that need to be manufactured, assembled, and calibrated. This consolidation lowers manufacturing costs while the integrated design maintains detection accuracy through optimized internal configuration
Solution Approach 2:
The patent uses a simplified single-element design that replicates the essential detection functionality of the two-element system without requiring duplicate components. This approach reduces manufacturing complexity and cost while preserving the core detection capability
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 cost-effective and simplified detection of door/window opening by measuring changes in resonant frequency, reducing system complexity and enhancing monitoring capabilities.
Implementation Method 1
an antenna having at least a first resonant frequency and a second resonant frequency associated therewith, the second resonant frequency being different from the first resonant frequency, the antenna having the first resonant frequency when in proximity to a door/window and the second resonant frequency when not in proximity to the door/window
Implementation Method 2
a high frequency oscillator operable for generating a high frequency oscillating electromagnetic signal for excitation of the antenna. Preferably, the article proximity indicator also includes a high frequency coupler coupled to the high frequency oscillator and to the antenna and operable for transmitting the high frequency oscillating electromagnetic signal generated by the high frequency oscillator to the antenna, the antenna being operable for radiating the high frequency oscillating electromagnetic signal
Data Source
AI summary
A door/window opening detector including an antenna having at least a first resonant frequency and a second resonant frequency associated therewith, the second resonant frequency being different from the first resonant frequency, the antenna having the first resonant frequency when in proximity to a door/window having a given dielectric constant and the second resonant frequency when not in proximity to a door/window having the given dielectric constant, and an alarm indication generator operable, in response to receiving an indication that a resonant frequency of the antenna has changed from the first resonant frequency to the second resonant frequency, for generating an alarm indication of opening of the door/window.