a problem with RF harvesting

Discussion in 'The Projects Forum' started by n.n.t87, Jan 11, 2014.

  1. n.n.t87

    Thread Starter New Member

    Jan 11, 2014
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    hello... i'm trying to design a RF energy harvesting circuit .. when i began to search the researches were about voltage doubler circuits with equal stage capacitors and when i tried to apply it with ADS it didn't work out...then the searching went on and on and nothing really came out ..i am really losing time ..none of the researches replied to me a i asked them ... no one is helping me with ADS .... i am lost and i have nothing in my hand ..so please any one could assist
    the RF source is 10dbm at two frequencies 1.8 and 2.4... i need 2 get 3.5 volt at the output ...
    sould i be using a voltage source or power source (power source includes 50 ohm resistance)
    there is also the matching problem some used it others didn't
    by the way i'm kindda new with ADS

    thank u 4 listening:(
     
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    If you could "harvest" useful amounts of energy from stray RF fields, don't you think everybody would be doing it (commercially)?
     
    shortbus likes this.
  3. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Probably because your thread title doesn't mention ADS, and also because few people here use ADS. Surely the ADS software comes with Help files?
    Is this a Homework project?
     
  4. wayneh

    Expert

    Sep 9, 2010
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    10 dbm? I'm too lazy to do the calculation for you, but I can tell you this is very little power. Your circuits will do well to capture a fraction of what's available. You need to do the math and figure out what you're dealing with.
     
  5. n.n.t87

    Thread Starter New Member

    Jan 11, 2014
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    well .. others started with Micro watts and still manged to get 5 volt ( as they wrote ) in their researches.. and when ever i mention ADS they seem to run away..
     
  6. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    What would you use the 5V for if it can deliver only uW ?
     
  7. DickCappels

    Moderator

    Aug 21, 2008
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    Diode-capacitor voltage multipliers are good for signals measured in volts, but for less than that, you will need to resort to active switches instead of diodes. Texas Instruments is a leader in this field and you find some inspiration on Texas Instrument's website.
    http://www.ti.com/lsds/ti/apps/alternative_energy/end_equipment.page
     
  8. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    Let me guess. The power to control the active switches is derived by harvesting RF power? :D
     
  9. Externet

    AAC Fanatic!

    Nov 29, 2005
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    n.n.t87:
    If your receiving antenna puts out 10 mW, what do you want to do with it ? Turn on a white led ?
    That is not the way to write a frequency < 1.8 or 2.4 > without units.
     
  10. #12

    Expert

    Nov 30, 2010
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    The lack of a practical application (useful power) could be explained if this is a homework assignment, but, what is "ADS"? 1.8 and 2.4 whats? Gigahertz?

    10dbm is in the 10 milliwatt range.
    A bit of mathing around gets me 1 volt peak into 50 ohms.
    dbm = 10 log (V^2/R*1mw)
    That is within the range that can be multiplied with real parts, diodes and capacitors...
    That's what I can come up with on the first try.

    (I showed my math so other people can tell if I am mistaken.)
     
    Last edited: Jan 12, 2014
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