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
    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
    U are forgetting the GSM transmitter frequency..!

    Google GSM frequencies.
  3. yuvi1

    Thread Starter Member

    Feb 1, 2013
    explain pls.
  4. vk6zgo

    Active Member

    Jul 21, 2012
    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
    thanks vk6zgo !
    it was very helpfull