2.4 - 2.5 GHz band?

Discussion in 'General Electronics Chat' started by skybox, Jun 2, 2010.

  1. skybox

    Thread Starter Active Member

    Mar 2, 2009
    68
    1
    Hi guys,

    I've been looking for a transmitter/reciever (transciever) that will transmit/receive in the following range: 2.4 - 2.5 GHz. The problem I am having is that most of the modules are 100 mW or lower. Due to our range requirements for our product, this might not suffice.

    Is 100 mW a power limit set by the FCC for this band?

    Sorry I am new to this stuff and this might seem like a noobish question, but I am just trying to get as much knowledge as I can before I finish my design.

    Thanks!
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,648
    2,348
  3. skybox

    Thread Starter Active Member

    Mar 2, 2009
    68
    1
    It's a compact application so I'll probably be using dipole SMA type antennas with a 3dBi gain or above
     
  4. skybox

    Thread Starter Active Member

    Mar 2, 2009
    68
    1
    The antenna would have to be omnidirectional
     
  5. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Here's an article that just gives you a rough idea of the bands:
    http://urgentcomm.com/techspeak/radio_truly_watershed_event/

    Keep in mind your transmitter output power vs antenna gain. If your product happens to exceed the FCC regulations under any circumstances, the FCC will have ABSOLUTELY NO sense of humor about it. They will confiscate all of your equipment, throw you in jail and slap VERY hefty fines on you, at the rate of around $10,000 per incident.

    It is YOUR responsibility to remain within the FAA's rules and regulations. Don't rely on that article for the FAA's actual regulations. You need someone there who will keep you from going to the hoosegow.
     
  6. skybox

    Thread Starter Active Member

    Mar 2, 2009
    68
    1
    Thanks for the reply. I will be buying off the shelf RF modules so I'd assume FCC guidelines are following.
     
  7. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    In that case, better buy transceivers that come with a matching antenna that are already certified to be in compliance with FCC rules/regulations.

    Sorry that I don't have a source for you. Just wanted to make you aware of a rather large pitfall that may be waiting for you if you choose badly.
     
  8. skybox

    Thread Starter Active Member

    Mar 2, 2009
    68
    1
    Thanks. Everything is helpful.

    I guess it is going to be hard to find a high power (1 Watt or higher) RF Transceiver in the 2.4 - 2.5 GHz range due to FCC guidelines.
     
  9. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    I doubt you will find anything even at 500mW with a 3dB gain antenna, as that would be the maximum allowed under FCC rules/regulations.
     
  10. coldpenguin

    Active Member

    Apr 18, 2010
    165
    9
    What is the distance you are trying to go?
     
  11. skybox

    Thread Starter Active Member

    Mar 2, 2009
    68
    1
  12. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
    Interesting.

    As I cautioned before, if you use an antenna that provides more than 0dB gain, you must reduce the power output from the transmitter.

    You are usually much better off to use much lower transmitting power, with a much more efficient antenna.

    If you don't know how to test this, or don't have the equipment to make certain that the emissions will be within FCC regulations, find someone who can do it for you.
     
  13. skybox

    Thread Starter Active Member

    Mar 2, 2009
    68
    1
    Yea I am reading and contacting people to follow FCC regulations. Thanks for all your help!
     
Loading...