Cell Phone Antenna

Discussion in 'Wireless & RF Design' started by mossman, Dec 17, 2010.

  1. mossman

    Thread Starter Member

    Aug 26, 2010
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    I have an internal antenna in my cell phone and there are two contacts that connect to the main PCB, one of which leads to the RF switch and the other connects to DC ground. However, on the actual antenna itself, these two contacts connect to each other. Can someone explain how this type of antenna works?
     
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    There is an inductance in the antenna between the two wires out of it. There may be continuity at DC, but at high frequencies, it appears as a load matched to the RF output impedance of the phone.
     
  3. mossman

    Thread Starter Member

    Aug 26, 2010
    131
    3
    Not sure I'm following you. I'm looking at the antenna and the two traces are clearly physically connected, about 1/4" before they connect to the PCB. Can you provide any useful links/references that explains this type of antenna?
     
  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    718
    Does the PCB trace make a "spiral" shape in a square?

    Can you post a photo of the PCB area and connection to the antenna?

    Some antennas are actually for decoration and use a "pad antenna" on the board.
     
  5. mossman

    Thread Starter Member

    Aug 26, 2010
    131
    3
    Last edited: Dec 17, 2010
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