Parallel Demodulator Circuit for Multi-Standard IC Card Signal Processing
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Solution Overview
Problem
Noncontact IC cards face challenges in simultaneously receiving and processing three types of reception signals (Type A, Type B, and ISO/IEC 18092) due to limited driving ability of the operating voltage generated from an RF signal, making it difficult to accept request commands within the specified 5 millisecond timeframe.
Innovation Solution
A semiconductor integrated circuit with a first and second antenna coupling terminal, a power circuit, and demodulator circuits that can demodulate signals of different modulation degrees, along with a determination circuit to identify the type of reception signal, allowing for parallel processing and efficient power management to reduce power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the IC card uses a single demodulator circuit to process reception signals, then the device complexity is reduced, but the IC card cannot simultaneously process multiple types of reception signals (Type A, Type B, and ISO/IEC 18092) within the 5 millisecond response time
Solution Approach 1:
The patent divides the demodulator circuit into multiple independent demodulator circuits (first demodulator for Type A, second demodulator for Type B and ISO/IEC 18092). Each demodulator is optimized for specific signal types, allowing parallel processing of multiple reception signals simultaneously, thus achieving the 5 millisecond response time requirement without excessive complexity
Solution Approach 2:
The patent implements dynamic control where the determination circuit selectively activates or halts specific demodulator circuits based on the detected signal type. This dynamic operation allows the system to maintain readiness for multiple signal types while reducing actual power consumption and operational complexity by only activating the necessary demodulator for the current signal being received
2Productivity
If the IC card activates multiple demodulator circuits to process different reception signal types in parallel, then the response time is reduced, but the power consumption increases beyond the limited driving ability of the operating voltage generated from RF signal
Solution Approach 1:
The determination circuit dynamically controls the operation state of each demodulator circuit based on the detected reception signal type. When Type A signal is detected, only the first demodulator operates; when Type B or ISO/IEC 18092 is detected, only the second demodulator operates. This dynamic activation ensures fast response capability while maintaining power consumption within the limited driving ability of the RF-generated operating voltage
Solution Approach 2:
The system uses the determination circuit to automatically detect the reception signal type and self-regulate which demodulator circuits should be active. This self-service mechanism eliminates the need for external power management control, allowing the IC card to optimize its power consumption automatically based on the incoming signal type
3Adaptability or versatility
If the IC card processes all three types of reception signals simultaneously using separate dedicated circuits, then the adaptability is improved, but the device complexity and power consumption increase significantly
Solution Approach 1:
The second demodulator circuit is designed with multi-functionality to handle both Type B and ISO/IEC 18092 reception signals. This universal design allows the IC card to support three different signal types (Type A, Type B, and ISO/IEC 18092) using only two demodulator circuits, thereby achieving high adaptability while avoiding the complexity of three separate dedicated circuits
Solution Approach 2:
The determination circuit detects changes in signal parameters (modulation degree, signal characteristics) to identify the reception signal type. By monitoring these parameter changes, the system can adaptively route the signal to the appropriate demodulator circuit, ensuring compatibility with multiple signal types without requiring complex pre-configuration for each signal type
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 the IC card to accept and process any type of reception signal for a short time, reducing power consumption and operating effectively under low driving voltage conditions, thereby meeting the 5 millisecond response requirement.
Implementation Method 1
The power circuit generates operating voltage by rectifying and smoothing the RF signal
Data Source
AI summary
A semiconductor integrated circuit and an IC card mounted with the same are provided, in which a signal of any one of at least three kinds of reception signals can be received for a short time. An RF signal from an antenna is supplied in parallel to a first and a second demodulator circuit included in a demodulator circuit. The first demodulator circuit demodulates a first reception signal of a first degree of modulation. The second demodulator circuit demodulates a second reception signal having a first communication start signal (SOF), and a third reception signal having a second communication start signal (Preamble). The demodulated output signals of the first and the second demodulator circuit are supplied to a determination circuit. When the demodulation output by the first demodulator circuit is determined, it is determined that the first reception signal is currently received. When the demodulation output of the second reception signal by the second demodulator circuit is determined, it is determined that the second reception signal is currently received. When the demodulation output of the third reception signal by the second demodulator circuit is determined, it is determined that the third reception signal is currently received.