Hi there,
We are using a radio module equipped with CC2420 2.4GHz RF transciever and a CC2591 front end (Up to 22-dBm Output Power). We would like to separate the antenna with an extension cable (e.g. LMR-400 Times Microwave) for about 30 feet away. Would this front-end be able to support such a long distance? What would be a reasonable max cable length to use?
Cable manufacturer's web site has the following loss calculator which returns the following results:
http://www.timesmicrowave.com/cgi-bin/calculate.pl
Product: LMR-400
Frequency (MHz): 2400
Run Length (Feet): 30
Attenuation (db/100 feet): 6.614
Attenuation (db/100 mtrs): 21.703
Average Power (kW): 0.34
Total Run Attenuation(dB): 2.0
Efficiency (%): 63.3
Thanks,
Bulut
Hi Bulut,
I'm pretty new here and I don't know yet exactly how this forum works, but just the other day I read an old application not. It has the literature number 11-08-26-003 and is named "HF Antenna Design Notes". It mainly addresses the issue of RFID antennas (which is my current interest) but it goes in detail into calculation and building of large frame antennas as well as it briefly talks about long cables to antenna and the influence especially at HF when the cable builds its own RFC cicuit.
Check it and see if it helps.
Harald
Bulut,
My answer is a little late, so likely by now you have completed the project. There is no problem with extending the antenna, you have calculated the loss and likely included it in your path budget so have no fear. You only concern with cables in RF are impedance, bandwidth and loss. You have taken those into account so I predict that when you return to the forum it will be to report success.
Doug Boone, P.E.