35 Threads found on edaboard.com: Pll As Demodulator
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Electronic Elementary Questions :: 29.01.2006 20:46 :: IanP :: Replies: 6 :: Views: 1743
it will depend on the pll usage
if u will use it as frequency synthizer the phase noise will be ur major target , and loop speed "settling time" , and for sure stabilty
if u will use it as demodulator the loop bandwidth , and speed will be ur major concern , and so on
Analog Circuit Design :: 22.04.2006 19:37 :: khouly :: Replies: 11 :: Views: 983
We using FM pll demodulator with a data slicer as FSK demodulator, my question is what is it a coherent demodulator or non-coherent demodulator?
And FSK demodulator has two another method:
1: general band pass filter and envelope comparator
2: match filter BPF and envelope comparator (...)
Digital communication :: 24.06.2007 23:16 :: wwfhm2002 :: Replies: 2 :: Views: 1763
For FM demodulation: If modulation index is low (max. phase deviation less than 1 radian), you could use a narrow-band pll as a phase demodulator. The output is the ouput of the phase detector, that after derivation gives the frequency.
This can work for low-index FM but not for FSK.
Why do you need a method other than take the control voltage o
Analog IC Design and Layout :: 22.02.2010 11:36 :: zorro :: Replies: 1 :: Views: 1143
A phase detector lowpass filter and a volatge controlled oscillator is enough to built a pll...IC version of pll is also available
RF, Microwave, Antennas and Optics :: 12.01.2006 22:44 :: electronics_kumar :: Replies: 7 :: Views: 1451
well costas loop basically used for "carrier recovery" of the incoming modulated signal on the receiver has NCO (numerical control oscillator) which functions as a pll to capture the incoming signal....
so the basic purpose of COSTAS LOOP is CARRIER RECOVERY....
Digital Signal Processing :: 11.06.2007 23:35 :: shahzad910 :: Replies: 3 :: Views: 1801
Therez lots of info on this Board itself.
Search for "pll" or Phase Lock in the Books upload/download or IEEE study papers.
Digital communication :: 04.05.2006 01:47 :: Renjith :: Replies: 6 :: Views: 2023
I want to callibrate a pll(74HC4046AN) as part of an mfsk demodulator for my diploma thesis.
17 different frequencies which correspond to 17 different analog voltages get in the phase
comparator. The pll have to lock each time at different frequency. I have tryed any
combination for RC filter but the best result is as shown at this (...)
Analog Circuit Design :: 29.09.2006 08:52 :: stsiligg :: Replies: 4 :: Views: 1238
I'm using a 74HC4046A pll/VCO to demodulate mono audio from an FM carrier. The carrier comes from a signal on CAT5e twisted-pair cable. (it rides on the common-mode on one pair which carries video on the differential mode) The carrier frequency is about 250kHz and the amplitude seen by the receiver is about 250mVp-p. Currently I'm modulatin
Analog Circuit Design :: 27.04.2007 15:57 :: akilpatrick :: Replies: 0 :: Views: 700
want to design a transmitter/receiver pair communicating via FSK modulation. I decided to design the transmitter side by a VCO. And I plan using LM565 on the receiver side.
At this point I need an explanat
RF, Microwave, Antennas and Optics :: 21.07.2008 14:36 :: hkBattousai :: Replies: 8 :: Views: 13835
10K + 10K pot combination is the external timing resistor required by the IC itself which is connected at the 8th pin. Why do we connect the 0.001uF capacitor between 7th and 8th pins of the IC? What is the import
Analog Circuit Design :: 21.08.2008 15:10 :: hkBattousai :: Replies: 3 :: Views: 8729
I have a theoretical question thats got be a bit stumped
It reads as follows:
"Design a frequency demodulator based on CD4046 pll. Use phase comparator R1 ≥ 5 kΩ, Rs ≤ 1 MΩ, C1 = 220 pF, VDD =+5 V, fO = 80 kHz,
C2 = 270 pF, fL = fC= ?40 kHz.
Electronic Elementary Questions :: 23.10.2008 17:16 :: T47 :: Replies: 2 :: Views: 5948
Most phase detectors require comparing the instantaneous phase received to some reference signal's phase. The reference signal can be generated in the receiver with some sort of narrowband pll circuit.
The problem you have in using an FM detector is....that the frequency of your signal is not changing. So converting the FM of your signal int
RF, Microwave, Antennas and Optics :: 17.05.2010 18:06 :: biff44 :: Replies: 3 :: Views: 969
Our circuit for 16-QAM MODEM with Dpll as its demodulator in simulink is showing a number of errors.Please help us with the circuit design.
Digital Signal Processing :: 14.03.2011 06:25 :: punam.ect :: Replies: 0 :: Views: 530
I did build and even used in practical links (private ones) the simple DSB-SC demodulator using a conventional pll though modified a little bit to restore the frequency and phase from the two bands only (since the carrier is suppressed). Even if the suppressed carrier is shifted, the loop still in lock in a good range (10% in the least).[/QU
RF, Microwave, Antennas and Optics :: 18.05.2011 18:27 :: FvM :: Replies: 8 :: Views: 763
88-108 is band 2 Broadcast Fm in the UK & Europe, this looks like band 2 1/2 (?) with non hi-fi frequency range and mono with excessive channel spacing and no pre/de-emphasis. Looks like a lost cause to me. But to get back to your question, get hold of a FM broadcast receiver and modify the front end to change the oscillator and RF frequency tunin
RF, Microwave, Antennas and Optics :: 12.12.2011 15:03 :: chuckey :: Replies: 4 :: Views: 824
This device is not an FM demodulator, it's a stereo demodulator. You have to demodulate the FM signal before it reaches the LA3361 then feed the 'raw' audio into the "MPX IN" pin so the pll can lock to the 19KHz pilot tone.
RF, Microwave, Antennas and Optics :: 21.12.2011 12:44 :: betwixt :: Replies: 3 :: Views: 597
The pll has a loop bandwidth. If you are inside of +/- the loop bandwidth from the VCO carrier, then the phase noise of the output is no better than 20 Log N + Reference phase noise. i.e. the reference phase noise as degraded by the pll.
If you are outside of the loop bandwidth, the phase noise can be as low as the free running VCO phase noise
RF, Microwave, Antennas and Optics :: 25.09.2012 22:35 :: biff44 :: Replies: 1 :: Views: 229
I am looking for an IC similar to 565 or 4046 to use as pll to demodulate FM broadcast signals.
(The problem is that the 565 is obsolete and I cant find any place around to buy some. the problem with 4046 is that it works with square wave and I need to have it worked by sinusoidal wave)
If you know other IC which are available in the m
Analog IC Design and Layout :: 03.01.2013 19:20 :: user105 :: Replies: 2 :: Views: 556
My thesis in year 1979 was a simple demodulator for Double Sideband Suppressed Carrier (DSB-SC) signal.
At that time, I did it for the IF AM frequency 455 KHz by using CD4046 (pll IC) and LM339 (quad comparator IC) to recover the phase and frequency of the suppressed carrier. But after I built the project I didn?t find the time to submit its paper
Electronic Elementary Questions :: 16.07.2013 10:15 :: KerimF :: Replies: 7 :: Views: 1024
".... The pll is a frequency-to-voltage converter of a different type than we have met before."
"Q. How do you make a frequency-to-voltage converter?... Designing pll systems is beyond the scope of this discussion, but if a 4000-series CMOS pll, the 4046, is used just as a phase detector (its VC
Professional Hardware and Electronics Design :: 18.12.2004 21:16 :: nicleo :: Replies: 1 :: Views: 6067
If you want to do it in analog you will have to use a pll or some frequency selective circuit whose output varies with frequency. If you want to do it in logic you can do some form of frequency counter.
The simplest solution would be a pll.
Electronic Elementary Questions :: 14.07.2005 02:13 :: flatulent :: Replies: 3 :: Views: 601
The normal way of making an FM receiver with digital frequency control is to make a superhetrodyne receiver that generates the local oscillator signal using a pll. The frequency generated by the pll is set by binary values in the programmable divider. Read some books about radio communications.
Making a fully digital broadcast FM receiver will
RF, Microwave, Antennas and Optics :: 01.06.2006 06:17 :: throwaway18 :: Replies: 3 :: Views: 1103
If you just want to use a black box and don't want to build the whole transmitter and receiver, you can use the FM modulator/demodulator passband present at the communication blockset=>Modulation=>Analog passband modulation.
If you would like to build the transmitter and the receiver, you can use the Voltage-controlled oscillator present at comm
Digital communication :: 08.08.2007 07:15 :: ieropsaltic :: Replies: 3 :: Views: 2929
only I/Q can give you phase information, if you want to demodulator signal from phase information, then you need I/Q, else only I or Q is needed such as FSK demodulator with pll.
Digital communication :: 02.10.2007 06:38 :: wwfhm2002 :: Replies: 2 :: Views: 1379
you can demodulate FM modulated signal using a pll loop
ASIC Design Methodologies and Tools (Digital) :: 01.11.2007 05:55 :: rania_hassan :: Replies: 9 :: Views: 794
I am implementing a digital QPSK demodulator (Data rate is: 42.4515 MBps) with VHDL for realizing on FPGA. For this, I have developed the sub modules such as:
(1- ) 16 bit Edge sensitive Phase-Frequency Detector (PFD) with up/down counter
(2- ) 32 bit Numerically Controlled Oscillator (NCO) with 9 bit outputs for Sin/Cos gene
Analog Circuit Design :: 18.06.2009 05:36 :: demod :: Replies: 0 :: Views: 846
In my opinion, the correct topic is FM-demodulation rather than spectral analysis. The problem can't be solved however without considering the characteristics of the baseband signal. As another point, the demodulator should be almost invariant to a varying carrier level. The most promising FM-demodulation methods are based on a pll tracking the car
Digital Signal Processing :: 02.09.2009 06:07 :: FvM :: Replies: 4 :: Views: 819
I'm looking to build a 24 and 36 GHz FMCW-type sensor system based on Hittite chips and microstrip patch antennas.
Do you have any experience and/or recommendations with these frequencies?
Initially I thought of the architecture as a VCO with pll that outputs Fo into a coupler; the through would go to a circulator before the antenna (either a
RF, Microwave, Antennas and Optics :: 15.05.2010 12:09 :: DanTheMan :: Replies: 4 :: Views: 844
For instance, did you hear of a simple AM demodulator that can be used for any modulation index; from zero (carrier only) to infinity (carrier suppressed)?
The one I designed (as an MS thesis), built and implemented in some of my private links (in the 80's) is based on a conventional pll with a minor modification (no coils, no
Digital communication :: 19.08.2011 11:25 :: Ahmed Alaa :: Replies: 11 :: Views: 9659
Analog Devices : Forms : ADIsimpll Version 3.3 Request for Software (good for designing pll,...)
Switchercad => Linear Technology - Design Simulation and Device Models
RF, Microwave, Antennas and Optics :: 27.02.2011 10:07 :: Kronstadt75 :: Replies: 1 :: Views: 1062
Please ask for me if any of your professors have already heard how to build a DSB-SC (Double Sideband Suppressed Carrier) demodulator based on a simple analog conventional pll (Phase Locked Loop). Obviously it could be done digitally as well.
I am asking on this, because on the internet I found out that till our days the 'only' (...)
Digital Signal Processing :: 17.07.2011 20:00 :: KerimF :: Replies: 4 :: Views: 575
pll is always good
ALU, DAC, ADC, etc. The difficulty level comes not from designs, but the specifications on the devices. Putting them in low specifications such as low bits, low resolutions will make it easier.
Analog IC Design and Layout :: 26.07.2011 13:16 :: florescent :: Replies: 6 :: Views: 759
As the vision comes from the Vision IF pll,this will be trying to phase lock to the FM IF, so its output will be following the VIF frequency modulation.
Electronic Elementary Questions :: 12.06.2012 13:04 :: chuckey :: Replies: 3 :: Views: 686
I read pll in Ramakant gayakwad reference book where they explained that VCO o/p frequency is N times the input frequency, so my query is we r trying to reduce VCO frequency towords value of Reference frequency so if VCo is producing N times higher frequency then they will never become same, as vco increases N times . In Somebook i read (at wikiped
Electronic Elementary Questions :: 03.10.2012 06:51 :: girish09 :: Replies: 2 :: Views: 273