Active Load Modulation Phase Compensation Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing solutions for contactless communication using active load modulation face challenges in compensating for delays caused by Process, Voltage, Temperature (PVT) variations and amplitude changes in the electromagnetic field, which affect the phase synchronization between the reader and the CE device.
Innovation Solution
A device with a receive circuit, a transmit circuit, and a compensation circuit that determines and applies a phase-shift value to compensate for delays due to PVT variations and amplitude changes, ensuring phase synchronization and stable communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If active load modulation is used with a small antenna in a CE device, then the device can generate its own electromagnetic field and achieve communication, but phase synchronization becomes unstable due to PVT variations and amplitude changes
Solution Approach 1:
The patent implements a feedback mechanism where the receive circuit processes the received signal and generates a clock signal that is fed back to the transmit circuit. This feedback loop allows the system to automatically adjust and maintain phase synchronization despite PVT variations and amplitude changes in the electromagnetic field
Solution Approach 2:
The patent changes the parameter of the clock signal by generating it from the received signal amplitude rather than using a fixed frequency source. This dynamic parameter adjustment allows the transmit circuit to adapt its phase to match the received signal, compensating for PVT variations and maintaining reliable communication
2Adaptability or versatility
If the receive circuit processes signals with varying amplitudes, then the device can handle different coupling conditions, but delay variations occur causing phase shifts
Solution Approach 1:
The receive circuit serves a dual function: it not only processes the received signal for data extraction but also generates the clock signal for the transmit circuit. This self-service approach eliminates the need for an external reference that would be affected by the same amplitude variations, thereby maintaining phase accuracy
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
The solution enables accurate compensation of delays, maintaining stable phase synchronization even with varying amplitudes, thus improving the reliability and efficiency of contactless communication between the device and the reader.
Implementation Method 1
a receive circuit configured to receive as an input a reception signal originating from an electromagnetic field intended to be received by an antenna
Implementation Method 2
contactless communication device by active load modulation... a transmit circuit comprising an output coupled to the antenna and intended to deliver on its output a modulation signal in phase with the reception signal
Data Source
AI summary
A device of contactless communication by active load modulation includes a receive circuit configured to receive as an input a reception signal originating from an electromagnetic field intended to be received by an antenna and to deliver as an output a first clock signal. A transmit circuit includes an output coupled to the antenna and operates to deliver on its output a modulation signal in phase with the reception signal. A compensation circuit is configured to compensate for a first delay of the first clock signal due to the receive circuit and to the amplitude of the reception signal. The compensation circuit operates to determine a phase-shift value to be applied to an input signal of the transmit circuit to compensate for the first delay.