Transponder Signal Phase Correction via Adaptive Sampling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing security systems face challenges in accurately and reliably detecting transponder signals due to device-specific phase shifts and component tolerances, leading to signal corruption and incomplete detection, especially when signals are read across multiple channels.
Innovation Solution
The security system employs a method where sinusoidal signals from transponders are sampled at four equidistant points within a period, allowing for the calculation of a phase shift, which is used for automatic phase correction, ensuring phase-synchronous sampling and reducing errors. This approach adapts sampling times based on the phase shift determination, converging to optimal sampling alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the transponder signal is sampled multiple times in the analog-to-digital converter with multiple sampling points, then the signal is digitized for processing, but device-specific phase shifts occur due to component tolerances leading to signal corruption and incorrect detection
Solution Approach 1:
The patent implements feedback by determining the phase shift from four sample values and using this information to correct the sampling timing. The control means adjusts the sampling times based on the calculated phase shift, creating a closed-loop system that continuously optimizes the sampling process to compensate for component tolerances and eliminate signal corruption.
Solution Approach 2:
The patent changes the sampling parameters dynamically by adjusting the sampling times based on the calculated phase shift. Instead of using fixed sampling points, the system modifies the sampling timing parameters to align with the actual phase of the transponder signal, thereby compensating for device-specific phase shifts and improving detection accuracy.
2Reliability
If the transponder signal is read into the computer unit via multiple channels with multiple analog-to-digital converters, then safety requirements are met through redundant reading, but complex external circuitry is required to synchronize the analog-to-digital converters
Solution Approach 1:
The patent enables self-service by allowing each analog-to-digital converter to independently determine its own phase shift from four sample values and automatically adjust its sampling timing accordingly. This eliminates the need for complex external synchronization circuitry, as each converter autonomously synchronizes itself to the transponder signal phase while maintaining redundant reading for safety requirements.
3Ease of manufacture
If fixed sampling times are used in the analog-to-digital converter, then the sampling process is simple, but component tolerances cause device-specific phase shifts leading to signal corruption
Solution Approach 1:
The patent introduces dynamics by transitioning from fixed sampling times to adaptive sampling times. The control means calculates the phase shift from four sample values and dynamically adjusts the sampling timing to match the actual signal phase. This dynamic adjustment maintains manufacturing simplicity while significantly improving sampling accuracy by compensating for component tolerances.
Data Source
Figure 1~2
Figure 3a~3c
Figure 4
AI summary
The invention relates to a security system (1) comprising at least one transponder (5) and at least one RFID reader (4). The RFID reader (4) reads a sinusoidal signal from the transponder (5) and transmits it to a computer unit (7) via an analog-to-digital converter (6). Furthermore, control means are provided in which the period of the sinusoidal signal is specified. In addition, the control means define four sampling points for sampling the sinusoidal signal during a sampling period, each equidistant from the others by one-quarter of the period of the sinusoidal signal. The analog-to-digital converter (6) obtains a sample value (S0 - S3) for each sampling point. The control means then determines the phase shift ϕ of the signal obtained from the samples relative to the sinusoidal signal from the sample values (S0 - S3) for the four sampling points.