Hand held reader design

[PM.1]

I was planning to design a hand held uhf rfid reader using this ic. Is it possible to design one using this ic? if yes how to design the antenna for this reader.? What are the challenges in designing an rfid reader. Please help.

[Marcel Rossignol]

Hi,

yes, it is possible to design a handheld RFID reader with the ST25RU3993.

This IC is even ideal for such kind of applications, because of the low power consumption.

The antenna design of handheld readers should at least cover the following:

1. Circular polarization: Tag readings independent from the tag orientation
2. Dimension: Not too big --> handheld dimensions!, not too small --> antenna gain & frequency range would decrease
3. Frequency range: FCC and/or ETSI and/or China region
4. Gain: as high as possible (for handhelds typical around 4dBic = 1dBiL)
5. VSWR: as small as possible
6. Impedance: 50 Ohm

Main challenges of UHF RFID reader design:

• Keeping TX path losses small
• Keeping RX path losses small
• EMC (FCC, ETSI, ARIB, ...)

The ST25RU3993 EVAL board is a very good starting point for your design.

If you use this as a reference, you will be successful.

Best regards,

Marcel