Well that depends specifically on the service provider (depends on which frequency your mobile operator is operating).
About the antenna types, don't have much idea but the commercially available femtocells so far have been using monopoles. Some research works currently going on are testing array based antennas but I haven't personally come across any femtocell (commercially available) that are using multiple array based antenna, they might be available though.
I want to design a femtocell antenna configuration. I am considering the band 7. which is dl 1620-1690 ul 1500-1570. is it oki? Will it be suitable for femtocell operation?
you should look for the cellular standard that your are gonna design femtocell for.
carrier frequencies for 2G, 2.5G,2.75G,3G 3.5G 3.75G and 4G are different and also they might use double band.
however any standard that you are gonna design femtocell for, has exactly the same carrier frequency bad as the BTS. actually femto cell should match to cell phone uplink and down link band that is used for communication with BTS. hence no difference is between femtocell and BTS carrier in any standard.
LTE band 7 is: 2620 - 2690 MHz for DL and 2500 - 2570 for UL.
If you are targetting LTE band 7, you should design your antenna to operate in the above range, not the one you mentioned.
The closest LTE band that operates in the spectrum range you have mentioned is LTE band 24: DL: 1525 - 1559 MHz and UL: 1625.5 - 1660.5 MHz - Well the frequencies are opposite for DL and UL compared to your case :))
aaahh, crap... Sorry I put "1" instead of "2" in the freq range in my second comment, sorry for that. Yah I am designing for that one (band 7), but finding it very hard to adjust with in a small space (within 45mm * 45mm). Any suggestions or any reference model please?
I have designed an microstrip multiband antenna...got the frequencies has 12GHz,13GHz 28 GHz and 38GHz... actually mmwave frequencies...can I use it for femtocells is my question??