INCREASE RANGE WITH 2.4 GH FULL DUPLEX INTERCOM

Discussion in 'Wireless & RF Design' started by Juan70, Nov 18, 2014.

  1. Juan70

    Thread Starter New Member

    Nov 12, 2014
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    0
    Is it possible to increase distance by boosting the units in anyway?
     
  2. skeptic

    Active Member

    Mar 7, 2010
    51
    9
    We don't know anything about your intercom units or how you are using them. Is it one main unit to many satellites or any unit to any other unit? How much range do you get and how much do you want? What kind of antennas do the units have? Do you need omni-direction or are the units mostly in the same direction? What kind of environment are you in - indoors? What is the building made of? How much metal is between the units including tinted glass? What is the difference between the transmit and receive frequencies of the the same unit. Does the unit use separate antennas for transmit and receive? What kind of modulation do the units use? What country are you in?
     
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  3. Juan70

    Thread Starter New Member

    Nov 12, 2014
    4
    0
    Wow. Ok here we go. Units have no antenna. They are the size of a match box. Transmit currently over 100 meters. Need it to transmit over 150. They are full duplex tour guide units made by acini. They will be used on a soccer field but under the referees shirt. We are in Australia.
    One unit is the master and the other two are slave units. Omni direction for sure.
    I hope I have answered all your questions. Hope someone can help
     
  4. skeptic

    Active Member

    Mar 7, 2010
    51
    9
    Before I'd do anything I would open the enclosure and judge the quality of the design. If it is all tiny surface mount components, I'd leave it alone because anything you do is likely to make it worse. If on the other hand it looks like it was designed to minimize cost you may be able to improve it. The order in which I would try to improve the range would be first the antenna and second the receive sensitivity. They do of course have antennas, even if they are inside the enclosure. The antenna is probably a printed circuit antenna. You might try cutting the trace to the antenna and replacing it with a short length of wire outside the box. It's possible the receiver has some desense due to the proximity of the transmitter. Anything you can do to isolate the receiver from the transmitter may help. If it's not enough you may try adding a preamp to the receiver input. Designing a low noise preamp at 2.5 MHz is not a trivial matter especially if you've never done it before. You should also try to filter out as much of the transmit signal as you can. A warning, this is not for amateurs. You do need to know what you are doing at 2.5 GHz. Not all the circuit design techniques at this frequency are obvious.
     
    Last edited: Nov 19, 2014
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