RFID Antenna Multiplexer With RF Energy Harvesting for Cable-Free Installation
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Solution Overview
Problem
Existing RFID systems with multiple antennas connected to a single reader require complex cabling and power supply systems, increasing installation costs and time.
Innovation Solution
An RFID antenna multiplexer that operates using only RF connections, harvesting signal energy to derive power and detect switch timing without the need for control signaling or DC power, allowing for efficient expansion of antenna coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If multiple antennas are connected to a single RFID reader using traditional multiplexers, then system coverage is improved, but installation complexity and cost increase due to required control signaling cables and DC power supply cables
Solution Approach 1:
The patent extracts and eliminates the control signaling cable and DC power supply cable from the traditional multiplexer system. The multiplexer is redesigned to operate autonomously by harvesting power directly from the RF signal, removing the disturbing elements (extra cables) that increased complexity while preserving the core function of connecting multiple antennas to a single reader.
Solution Approach 2:
The multiplexer is designed to be self-powered by harvesting energy from the RF signal it receives from the reader. This self-service capability eliminates the need for external DC power supply cables and control signaling cables, as the multiplexer generates its own operating power from the signal environment, thereby reducing installation complexity while maintaining expanded system coverage.
2Area of stationary object
If multiple antennas are connected to a single RFID reader, then servicing area is expanded, but installation time and cost increase due to additional power supply and data cables
Solution Approach 1:
The patent removes the time-consuming installation requirements for separate power supply cables and data cables by designing a multiplexer that operates without these connections. The extracted elimination of these cable requirements directly reduces installation time while preserving the expanded servicing area capability.
Solution Approach 2:
By making the multiplexer self-powered through RF energy harvesting, the system eliminates the need for complex power supply and data cable installations. This self-service approach significantly reduces installation time and complexity while maintaining the ability to service a larger area through multiple antenna connections.
3Reliability
If control signaling cables and DC power cables are used with RFID multiplexers, then reliable operation is achieved, but system cost and installation complexity increase
Solution Approach 1:
The multiplexer achieves reliable operation through self-powered design, harvesting sufficient energy from the RF signal to maintain stable functioning. This eliminates the need for external DC power cables and control signaling cables, reducing system complexity while preserving operational reliability through autonomous power generation and embedded control logic.
Solution Approach 2:
The RF coaxial cable is given multiple functions: it simultaneously transmits the RF signal for antenna operation and provides power for the multiplexer operation. This multi-functionality eliminates the need for separate power and control cables, reducing system complexity while maintaining reliable operation through integrated signal and power transmission.
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
Reduces costs and complexity by eliminating the need for control signaling and DC power cables, enabling efficient installation and operation of RFID systems with multiple antennas.
Implementation Method 1
harvesting signal energy to derive power
Implementation Method 2
detect switch timing based on a reduction in RF power from the reader as detected at the input port
Data Source
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AI summary
Aspects and features of this disclosure include a radio frequency identification (RFID) antenna multiplexer. An RFID reader and an RFID system using the RFID antenna multiplexer are also disclosed. The multiplexer includes multiple output ports. Each of at least some of the output ports is connectable to an antenna or another device. In some aspects, a logic circuit in the multiplexer is configured to cause a radio frequency (RF) switch to select an output port from the multiple output ports to connect to the input port based upon a reduction in RF power at the input port. In some aspects, the multiplexer includes an energy harvester connected to the input port to harvest signal energy from the RFID reader and a storage device connected to the energy harvester to store the signal energy and supply power to the multiplexer using the signal energy.