RFID Power Amplifier Variable Modulation Low Noise
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Solution Overview
Problem
Conventional RFID system read/write stations face challenges in achieving high efficiency and variable modulation while maintaining low noise levels, due to fixed modulation degrees and high power losses, which necessitate complex cooling and increased energy consumption.
Innovation Solution
A low-noise transmission device with a high-efficiency E output stage and a control device that modulates the driver output voltage using two separate DC voltage sources, allowing for variable modulation by switching between driver and modulator supply voltages, reducing component complexity and power requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the transmitter uses high transmission power to communicate with distant transponders, then the communication range is extended, but the power loss in the transmission output stage increases and requires complex cooling measures
Solution Approach 1:
The patent applies parameter changes by implementing variable transmission power output through a controllable transmission output stage. The system can adjust the transmission power level based on the distance to the transponder, using lower power for nearby transponders and higher power only when necessary for distant communication. This resolves the contradiction by enabling extended range when needed while minimizing power loss during normal operation.
Solution Approach 2:
The transmission output stage is designed with dynamic control capabilities, allowing the transmission power to be adjusted in real-time based on operational requirements. The system transitions from a fixed high-power configuration to a dynamically adjustable power system that optimizes the balance between communication range and energy efficiency, reducing unnecessary power loss while maintaining the ability to reach distant transponders when required.
2Length of stationary object
If the transmitter operates with high transmission power, then distant transponders can be activated, but the noise from the transmitter masks the weak response signals from transponders
Solution Approach 1:
The system dynamically adjusts transmission power based on the communication phase and distance requirements. During transponder activation, higher power is used to ensure sufficient energy transfer. During response signal reception, the system switches to lower power operation to minimize self-generated noise, enabling the receiver to detect weak transponder responses without masking from transmitter noise.
Solution Approach 2:
The transmission process uses periodic action with distinct phases: a high-power transmission phase for activating distant transponders, followed by a low-power reception phase for capturing weak response signals. This periodic switching between high and low power states allows the system to overcome the noise masking problem while maintaining extended communication range capability.
3Adaptability or versatility
If the degree of modulation is fixed, then the hardware design is simplified, but the system cannot adapt to different transponder technologies and applications
Solution Approach 1:
The system implements dynamic modulation control where the degree of modulation can be adjusted based on the transponder type and application requirements. The modulation depth is made variable through control circuitry that adapts the modulation parameters in real-time, allowing the same hardware to efficiently communicate with different transponder technologies without requiring multiple specialized hardware configurations.
Solution Approach 2:
The transmission device is designed with universal functionality to handle multiple transponder technologies through a single hardware platform. The controllable transmission output stage and adjustable modulation parameters enable the system to serve various applications (e.g., short-range high-modulation for robust communication, long-range low-modulation for energy efficiency) without requiring separate dedicated hardware for each application type.
4Loss of energy
If the transmission output stage has poor efficiency, then less power is lost as heat, but more electrical energy must be supplied increasing component and energy outlay
Solution Approach 1:
The transmission output stage implements parameter changes through variable power operation. By adjusting the transmission power level based on actual communication needs, the system optimizes the balance between power loss and energy consumption. The controllable output stage can operate at lower power levels for nearby transponders, reducing both heat dissipation requirements and overall energy consumption, while maintaining the capability to handle high-power transmission when necessary for distant communication.
Data Source
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AI summary
The device has a power amplifier with a driving device (35), where transmitting power of the amplifier is varied by variation of a transmitting supply voltage, and a modulating level of transmitting signals is varied by variation of the supply voltage. A transmitting supply voltage source (33) is fed by two direct current voltages, in which direct current voltage with high valve determines the amplitude of unmodulated transmitting signals and with low valve determines the amplitude of modulated transmitting signals.