How to increase RFID wireless system based on M24LR04E read range?

[Farzaneh]

Hi there,

My PhD project focuses on RFID-based wireless capacitive sensors.

The Tag is M24LR04E, and I'm using a reader from the M24LR-Discovery kit with a CR95HF transceiver board and a 2 turn 424nH antenna.

Current read range is 45 millimetres. My application requires a read range of around 100 mm. How can I expand the read range?

In the [1] RFID interface of the tag is accomplished by connecting the EEPROM to a double-layer PCB antenna coil with 12 trace convolutions, resulting in a square with exterior dimensions of 15.7 mm and a measured self-inductance of 4.6H (4.7H theoretical). The RFID reader was an STMicroelectronics (DEVKIT-M24LR-A) device. With this configuration they achieved reader-tag communication distance is 11cm�? . 

I am composing a strategy that I propose to use with them to increase the read range.

1. Increase the size of the reader antenna by employing a one-turn antenna

2. Changing the tuning capacitance of the reader such that a larger inductor can be used to get a larger antenna size.

3. Using your DEVKIT-M24LR-A antenna, which is already has  larger Antenna

4. Using a double-layer PCB antenna coil, which I am not sure has effect on read range.

I would really appreciate it if you could advise me as to which has the greater impact on read-range or Is there any other solution to increase the read range?

Regards

Farzaneh Beigi

[1]: M. Caldara, B. Nodari, V. Re, and B. Bonandrini, "Miniaturized and low-power blood pressure telemetry system with RFID interface," Procedia Engineering, vol. 87, pp. 344-347, 2014.

[Brian TIDAL · Accepted solution]

https://www.st.com/en/nfc/st25r3911b.htmlHi,

for similar questions, see:

• https://community.st.com/s/question/0D53W000006r47nSAA/st25r95-distance-range-output-power-inductor-as-antenna
• https://community.st.com/s/question/0D53W00000THvKbSAL/how-to-increase-the-range-of-cr95hf-receiver-on-a-custom-pcb

Achieving a 100mm read range would be less challenging with readers having an higher RF output power than ST25R95/CR95HF such as ST25R3911B or ST25R3916 (see Discovery kit for the ST25R3911B or Discovery kit for the ST25R3916).

Rgds

BT

[Farzaneh]

Hi there,

Thank you for your prompt and informative response. Using a few new antennas and ST25R3911B readers, I was able to achieve a read range of 10 centimetres with a few of them. However, this reading range is for data transfer, and the power transfer read range in M2404lr was only 3 centimetres when energy harvesting was used. What does it seem to you? Am I doing something wrong, or is it possible to expand the power transfer read range?

Thanks again for your support

Best regards

Farzaneh