QUOTE(keneng79 @ Oct 16 2011, 10:29 PM)
Hi Coolstore, your new antenna comes with dual band? what is the gain in dBi?
keneng79, this is a very good question.
Better replied from 2 angle : antenna technical and the 3g frequency pros/cons.
The so-called dual band 3G operation is going to use low frequency 900MHz and high frequency 2100MHz.
Antenna technical - got high gain for dual band 900MHz+2100MHz by 1 antenna alone?
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1) Since 900MHz and 2100MHz are 2 far away separated frequency range. Pro Antenna factory enginneer said it is
not possible now to provide a super high gain value for that both 2 frequency range by an antenna alone.
It is now available at lower gain, ie around 10dbi to cover these dual bands 900MHz ~ 2100MHz.
High gain such as 16dbi or above available for specific frquency in order to provide powerful gain just for that specific spectrum, so we can see high gain for 900MHz range alone or high gain for 2100MHz range alone, but not combined in 1 yet.
p/s: ppl may has been misleaded by so many misleading product info listed in ebay or other sites, which most these antenna seller are from china/hk. They wrote 900MHz - 2100MHz (carefully look at the symbol - means To) with a high gain value in product description, that really a duping manner to sell! (last time i did chat with 1 seller, and asked tripple times for that confirmation, then the seller finally admitted the high gain is for 2100MHz only, claimed typo error in web site (really? typo error or duping technique?) i took the screenshot of that chat conversation, haha
If that kind antenna made out of US MIT or DoD, then i more believe that is a breakthrough invention antenna.
if i not mistaken, 1 of our local university is embarking on project to produce wide frequency high gain antenna, don't know how now.
3G dual band frequency - 900MHz and 2100MHz ?
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1) 3G are run in 2100MHz high frequency in original design, because higher frequency can carry more data, then can provide faster speed.
2) But then they also started run in low frequency 900MHz since this year by maxis/celcom. (started already or not, i no sure). It seems Digi and U-Mobile not follow suit, they keep using single 2100MHz.
3) High / Low Frequency Pros & Cons:
Higher frequency can carry more data, so can provide faster speed, but they weak in terms of indoor signal penetration (indoor signal weak)
Lower frequency carry less data, so provide slower speed, but they good at indoor signal penetration (indoor signal stronger)
So it is understandable why U-Mobile still stick to 2100MHz and now provide latest 42Mbps plan.
Some querries/doubt i heard against the 900MHz 3G band were:
a) yes, 900MHz do provides better indoor signal, but carry slower speed, is that still called 3G or GSM plan instead? is that duping? (making ppl see "good 3G signal" in house but instead running at 900MHz?)
b) if 900MHz can provide 3G speed, why 3G was implemented in 2100MHz initially? if so, we should already can get 3G in GSM 900MHz era, why need third-generation 3G 2100MHz?
c) how do i avoid using 900MHz 3G spectrum and keep using 2100MHz?
For these questions, better find answer from 3G pro. to answer.
But for ©, i think either:
i) get 2100MHz 1 band only 3G modem.
ii) set manually in modem system program (if this option available)
ii) if dual band is an auto switching techniques, ie if modem sense 900MHz signal stronger will switch to it, then put on high gain 2100MHz antenna to make 2100MHz signal strong so that no swictching to 900MHz when come to indoor. but just my guessing only.
Oct 12 2011, 11:27 AM
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(maybe they also heard the voice of dongle users, not always use it on-the-road one ..)
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