Question about Wavelength in cellular phones

Discussion in 'General Electronics Chat' started by yuvi1, Jan 14, 2014.

  1. yuvi1

    Thread Starter Member

    Feb 1, 2013
    37
    0
    hi all
    i have a question about Wavelength in the cellular world.

    it is known that we can calaulate the Wavelength from this formula :
    Wavelength = c / f .
    so for example , if we use this frequency of 2.1 GHz
    we get a Wavelength of : 14.285 centimeter.

    so i'm asking if it is necessary that the antenna inside the phone must be
    in the same length of the wavelength ? because when i open the phone i see that the antenna is very small and even if its folded it's still smaller than the wavelength .
    it's maby possible with the use of some kind of circuit or a match circuit ? , or it is not necessary to be in same length ?


    thanks !
     
    Last edited: Jan 14, 2014
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
    8,754
    760
    U are forgetting the GSM transmitter frequency..!

    Google GSM frequencies.
     
  3. yuvi1

    Thread Starter Member

    Feb 1, 2013
    37
    0
    explain pls.
     
  4. vk6zgo

    Active Member

    Jul 21, 2012
    677
    85
    The classic lengths for antennas are λ/2 & λ/4,so,no,they don't have to be a full wavelength.

    You can use considerably smaller lengths by means of various forms of "matching" networks.

    These don't work as well as a properly designed λ/2 or λ/4,but are mandated by the small size required by marketing.
     
    Last edited: Jan 14, 2014
  5. yuvi1

    Thread Starter Member

    Feb 1, 2013
    37
    0
    thanks vk6zgo !
    it was very helpfull
     
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