+ Post New Thread
Results 1 to 11 of 11

26th September 2006, 17:39 #1
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.

26th September 2006, 18:07 #2
 Join Date
 Oct 2004
 Posts
 83
 Helped
 16 / 16
 Points
 2,602
 Level
 11
frequency multiplier circuit diagram
You need to specify your input frequency range.
1 members found this post helpful.

26th September 2006, 18:07

26th September 2006, 23:41 #3
 Join Date
 May 2006
 Location
 Hong Kong
 Posts
 89
 Helped
 8 / 8
 Points
 1,746
 Level
 9
simple frequency doubler
a mixer followed by a highpass filter?

27th September 2006, 01:49 #4
 Join Date
 Jan 2003
 Location
 Ireland
 Posts
 268
 Helped
 19 / 19
 Points
 4,313
 Level
 15
frequency doubler circuit
Simple frequency doubler for squarewave.

27th September 2006, 03:46 #5
analog frequency doubler
Originally Posted by 10kangstroms
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:
Originally Posted by bunalmis
will the output have a 50% duty cycle?

27th September 2006, 03:46

27th September 2006, 05:34 #6
 Join Date
 Sep 2006
 Posts
 69
 Helped
 4 / 4
 Points
 1,526
 Level
 8
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

27th September 2006, 10:29 #7
 Join Date
 Jan 2003
 Location
 Ireland
 Posts
 268
 Helped
 19 / 19
 Points
 4,313
 Level
 15
frequency multiplier circuit design
Originally Posted by zhangseong
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.

27th September 2006, 13:45 #8
square wave frequency doubler
Originally Posted by 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 flipflop circuit to divide the signal ? help please....thanks
Added after 16 minutes:
Originally Posted by timo67
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.

27th September 2006, 18:18 #9
 Join Date
 Sep 2006
 Posts
 69
 Helped
 4 / 4
 Points
 1,526
 Level
 8
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

27th September 2006, 18:18

28th September 2006, 14:41 #10
 Join Date
 Oct 2004
 Posts
 44
 Helped
 5 / 5
 Points
 2,290
 Level
 11
pll frequency doubler
Use a phase lock loop,

4th October 2006, 09:08 #11
frequency doubler pll
Originally Posted by bunalmis
i need more delay like delay a quarter of a input square wave
ragards
+ Post New Thread
Please login