Notes about RFID Antenna design

[balaguru thavamani]

Info on RFID Antenna

Need reference books for RFID Antenna design.
is any book available in this forum regarding RFID Antenna Design?

Advance Thanks.

 

[Leilon]

Info on RFID Antenna

also I need

 

[Eugen_E]

Re: Info on RFID Antenna

Depends on the frequency range. For LW, MW, HF RFID, the antenna is a coil and u can use microchip application notes for design:
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For microwave, the design is similar to communications antennas, after design
you need to simulate.

 

[jallem]

Info on RFID Antenna

What frequency?

 

[balaguru thavamani]

Re: Info on RFID Antenna

for UHF (860-960 MHz)

 

[atul_microwaves_antenna]

Re: Info on RFID Antenna

HI,
I think this might help you.It discusses about RFID loop antennas and Antenna circuit designs.

Bye.

 

[mainak001]

Re: Info on RFID Antenna

i think u can't design RFID in UHF band . This band is now totally licensed to MObile spectrum .. Nad 2.4 GHz band is also used to design microwave oven . So now the total RFID design shifts to UNII band . I have aa design in 5.88GHz . If u need ican give u . Please inform if u need that !

 

[balaguru thavamani]

Re: Info on RFID Antenna

i think u can't design RFID in UHF band . This band is now totally licensed to MObile spectrum .. Nad 2.4 GHz band is also used to design microwave oven . So now the total RFID design shifts to UNII band . I have aa design in 5.88GHz . If u need ican give u . Please inform if u need that !

Now I'm in the learning stage of RFID Tag Antenna.It will be helpful if u send those design.

Thanks

 

[jallem]

Info on RFID Antenna

There are RFID system designs for 125KHz, 13.5MHz,
900 MHz band(908-915), 2.4 GHz and 5GHz.
However, balaguru, I have not seen a book dedicated
only for RFID antenna design. Over time I
have collected papers talking about antennas
in the 900 MHz band mostly from IEEE.
Some of them you can find here. A search
is your best bet since some are very
specific. Search for VHF RFID ANTENNAS.

For low frequencies(125 khZ and 13.5 MHz) is not
an antenna but a coupler. Some people like to call it
antenna but I refuse to do so, since there is not
far field radiation just magnetic coupling.

For 900 and up, the antenna, also called tag, is located
very close to the item to ID. If this item is metallic then
the antenna becomes very special, low impedance, low
efficiency, etc. Some designers use an absorber behind the
antenna for impedance purpose. One design can not fit all
since there are many kind of packaging materials(carton,
plastic, glass, metals, wood, etc). Also for 900 MHz can not
be used a microstrip antenna since the ground plane separation
is too big and render the antenna too bulky. However, 900
MHz is the band most used regarding long distance. The
band in 2.4 GHz is also used for RFID but is not very popular yet.

 

[streamlet]

Info on RFID Antenna

to mainak001:
I can't agree with you upon the absence of UHF band, since there is international standard of UHF RFID published, like ISO18000-6c.

to balaguru:
jallem really gave a good summary above. I just want to supplement some info here.

As you may already know, dipole-type antenna is the most popular candidate for UHF RFID tag antenna. However, nearly all practical tag antenna designs are based on modified shapes, for example, meander-line antenna, folded-dipole. It's not difficult to find the motivation under this kind of modification is miniaturization.

Another possible is loop antenna, since they also own omni-directional pattern and small-size. Furthermore, loop can be used to enhance the near-field so as to improve the RFID system performance when the tag is very close to the reader.

A seldom case is microstrip antenna (MPA). However, it's suitable for some special case, like on metals. We can use the gnd plate of MPA to make the tag antenna immune to the external metal surface. In fact, modified MPA has been under rich study here, like PIFA.