2.4 GHz Duck antenna on 868 mHz device

Wireless & IoT
1

Hi,

I need some advice:

I have 2x 2.4 Ghz duck antennas and i have recently ordered 2x 868 mHz Xbee’s with RP-SMA.

Is it possible to use a 2.4 Duck antenna with a 868 mHz device?

And how will this affect the range?

Thanks,

Ingmar

2

I wouldn’t recommend it - you’re likely to get very poor performance. The bandwidth of these antennas is typically tens of megahertz.

3

Use 868 MHz antennas. Anything else is a waste of time.

4

Dear Ingmar-

For 868 MHz, the 2.4 GHz ‘rubber ducky’ will be electrically small. You won’t get as good a current distribution on the antenna as you would if it was designed to resonate at 868 MHz, so you won’t get as much directive gain.

There is also the bigger problem of impedance matching. Your electrically small antenna will probably present a mismatched impedance to the “RF in/out” of your radio, causing much of the RF power (either incident on the antenna that you would like to receive or coming from the radio that you would like to transmit) to be unavailable.

You might be able to fix the matching problem, but you will need some pretty specialized equipment to do the job. If it was me, I would go ahead and get the proper antenna.

Hope this helps…

Mark

ingmarHendriks:
Hi,

I need some advice:

I have 2x 2.4 Ghz duck antennas and i have recently ordered 2x 868 mHz Xbee’s with RP-SMA.

Is it possible to use a 2.4 Duck antenna with a 868 mHz device?

And how will this affect the range?

Thanks,

Ingmar

5

Thanks for your help. I will buy a 868 mHz antenna.

6

Try the “Splatch”, very small and cheap: http://www.antennafactor.com/resources/ … 868-sp.pdf