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    frequency doubler

    i need a simple design of how to make the input frequency become double ...any circuit designer can help? i will appreciate if someone can give me a hand on this.

    •   Alt26th September 2006, 17:39

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    frequency multiplier circuit diagram

    You need to specify your input frequency range.



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    simple frequency doubler

    a mixer followed by a high-pass filter?



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    frequency doubler circuit

    Simple frequency doubler for squarewave.



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    analog frequency doubler

    Quote Originally Posted by 10kangstroms
    You need to specify your input frequency range.


    err....i am very new to circuit design....what specification should i concern about? about the frequency , i think as big as posible lo...hehe...but as long as i can maintain 50% duty cycle is the most important

    Added after 31 minutes:

    Quote Originally Posted by bunalmis
    Simple frequency doubler for squarewave.
    thanks for the circuit....but if my input has a high frequency ...for example 100Mhz.....can i use this circuit? if cannot , do you know what circuit can be used? thanks alot

    will the output have a 50% duty cycle?



    •   Alt27th September 2006, 03:46

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    frequency doubler design

    Hi
    The are many methods for doubling a frequency
    it depends on
    1 the type of signal (square or sine or ...)
    2 The range of the frequency (very low, low, medium, high, very high, hyper...)
    3 The stability of the frequence you want to double (is it a single frequency ar many frequencies) what is the frequency range?

    Methods I know are:
    1 PLL (Phase locked loop)
    2 Non linearity to produce hamonics of the signal (full wave rectifier for example) followed by an adequate filter
    2 Mixer (in reality mixers translate the frequency, but you can considerate that Fx2 is the same as F+F) this method is also non linearity...
    3 monostables trigged by rise edge and fall edge of the signal (square)
    ...

    Hi

    Added after 7 minutes:

    I forgot...
    If your signal is a random signal (speech for example) you can use FFT (fast fourrier transform) to double its frequency
    it depends also if you want a real time response or not

    good luck



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    frequency multiplier circuit design

    Quote Originally Posted by zhangseong
    ...but if my input has a high frequency ...for example 100Mhz.....can i use this circuit? if cannot , do you know what circuit can be used? thanks alot

    will the output have a 50% duty cycle?
    You can produce %50 duty If input signal frequency is fixed and has %50 duty. You can calculate the appropriate R and C values. You can use monostable for non symetric input.

    100 Mhz no problem you may select fast logic family but I dont suggest this circuit because duty drift by temprature.

    PLL seems good solution for you.



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    square wave frequency doubler

    Quote Originally Posted by bunalmis

    PLL seems good solution for you.
    thanks bunalmis

    can you help me in this PLL ? i dunno which simulator have this component and what should i connect the PLL...( a circuit diagram connection if can)
    is this PLL a frequency multiplier also? to get a 50% duty cycle, i should use another flip-flop circuit to divide the signal ? help please....thanks

    Added after 16 minutes:

    Quote Originally Posted by timo67
    Hi
    Methods I know are:
    1 PLL (Phase locked loop)
    2 Non linearity to produce hamonics of the signal (full wave rectifier for example) followed by an adequate filter
    2 Mixer (in reality mixers translate the frequency, but you can considerate that Fx2 is the same as F+F) this method is also non linearity...
    3 monostables trigged by rise edge and fall edge of the signal (square)
    ...
    specification
    1. square wave input
    2. square wave output(50%)
    3. 100Mhz frequency

    can you give a circuit diagram for each of the approach that you gave?
    1. for PLL, what simulator can get the component? cadence? Hspice or pspice?
    2. full rectifier.....is this AC current to DC current? can this get 50% suare wave
    output?
    3. for mixer....is this the one Xored 2 signal( one been delayed)?
    4. can you give example for the FFT option?

    thanks timo67 ...your help is very helpul to me.



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    mixer as frequency doubler

    100MHz is a relative high frequency
    for this reason I think the advice of bunalmis is wise
    If you need a very precise duty cycle of 50% you can for example doubel you requency twice untill 400MHz and then divize it by 2 with a JK frequency divider.

    good luck



  10. #10
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    pll frequency doubler

    Use a phase lock loop,



  11. #11
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    frequency doubler pll

    Quote Originally Posted by bunalmis
    Simple frequency doubler for squarewave.
    i use pspice to simulate the result, but it seem only can produce a zero crossing output...
    i need more delay like delay a quarter of a input square wave

    ragards



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