Booster Antenna Coupler Coil RFID Smart Card Read Range
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing secure documents with RFID chips, such as electronic passports and smart cards, face challenges in achieving optimal coupling between the module antenna and the booster antenna, leading to limited read/write range with external readers.
Innovation Solution
Incorporating a booster antenna with an outer winding and an inner winding, connected via a coupler coil, which is inductively coupled with the module antenna, enhancing electromagnetic coupling and increasing the read/write range by configuring the windings in a quasi-dipole arrangement with reverse phase connections.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a module antenna is directly connected to the RFID chip, then the device complexity is reduced, but the read/write range with external readers is limited
Solution Approach 1:
A booster antenna is introduced as an intermediary element between the module antenna and the external reader. The booster antenna is inductively coupled to the module antenna through a coupler coil, acting as a mediator to extend the electromagnetic field reach and thereby increase the read/write range without directly complicating the chip connection structure.
Solution Approach 2:
The coupler coil is positioned within or adjacent to the booster antenna structure, creating a nested arrangement where the coupler coil is embedded in the booster antenna assembly. This nested configuration allows the smaller coupler coil to be integrated within the larger booster antenna structure, maximizing space utilization while achieving the desired coupling effect.
2Length of stationary object
If a booster antenna with coupler coil is added to enhance coupling, then the read/write range is increased, but the device complexity increases
Solution Approach 1:
The coupler coil and booster antenna are merged into a single integrated assembly rather than being separate components. The coupler coil is positioned and connected to the booster antenna in a unified structure that reduces the number of discrete parts and simplifies the overall coupling mechanism, thereby limiting the increase in device complexity.
3Reliability
If the coupler coil is positioned close to the module antenna for better coupling, then the electromagnetic coupling is enhanced, but the area available for other components is reduced
Solution Approach 1:
The electromagnetic coupling is enhanced locally at the specific position where the coupler coil interfaces with the module antenna, while the rest of the card body maintains its standard layout. The booster antenna is positioned at the periphery or in available spaces, allowing optimal coupling at the critical interface without compromising the overall area availability for other components.
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
This configuration significantly enhances the read/write range between the data carrier and external readers, improving the operational efficiency of secure documents like smart cards and electronic passports.
Implementation Method 1
a coupler coil (CC), connecting the outer end (OE, b) of the outer winding (OW) and the inner end (IE, e) of the inner winding (IW)
Implementation Method 2
a booster antenna (BA) on the card body (CB) of the smart card and inductively coupled with the module antenna (MA)
Data Source
Figure 1A~1B
Figure 2A~2B
Figure 3
AI summary
A data carrier such as a smart card comprising an antenna module (AM) and a booster antenna (BA). The booster antenna (BA) has an outer winding (OW) and an inner winding (IW), each of which has an inner end (IE) and an outer end (OE). A coupler coil (CC) is provided, connecting the outer end (OE, b) of the outer winding (OW) and the inner end (IE, e) of the inner winding (IW). The inner end (IE, a) of the outer winding (OW) and the outer end (OE, f) of the inner winding (IW) are left un-connected (free floating). The coupler coil (CC) may have a clockwise (CW) or counter-clockwise (CCW) sense which is the same as or opposite to the sense (CW or CCW) of the outer and inner windings.