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Entry  Sun Jan 30 19:26:03 2011, Koji, Summary, Green Locking, Prototype freq divider freq_divider.pdfIMG_3813.jpgIMG_3814.jpg
    Reply  Wed Feb 2 03:27:20 2011, Koji, Summary, Green Locking, 85MHz Freq divider freq_divider.pdfIMG_3816.JPGIMG_3818.JPG
       Reply  Wed Feb 2 09:56:55 2011, Koji, Summary, Green Locking, Installed the freq divider and Rana's PFD freq_divider_installation.pdf110201_freq_divider_output.pdf
          Reply  Wed Feb 2 10:44:26 2011, Koji, Summary, Green Locking, Freq fluctuation measured by the freq divider and Rana's analog PFD 110201_green_freq_fluctuation.pdf
             Reply  Wed Feb 2 12:55:34 2011, Koji, Summary, Green Locking, Freq fluctuation measured by the freq divider and Rana's analog PFD 
             Reply  Sat Feb 5 23:03:04 2011, rana, koji, Summary, Electronics, Analog Frequency Discriminator: splitter + mixer + long cable mixer.pdfUntitled.pngfsm.png
                Reply  Sun Feb 6 02:29:28 2011, rana, Update, Electronics, Analog MFD: longer cable mfd18.png
Message ID: 4228     Entry time: Sun Jan 30 19:26:03 2011     Reply to this: 4237
Author: Koji 
Type: Summary 
Category: Green Locking 
Subject: Prototype freq divider 

A prototype freq divider has been made which works up to ~40MHz.

74HC4060 (14bit binary ripple counter) divides the freq of the input signal, which is comverted by the comparator LT1016
into the rectangular signal. The division rate is 2^14.

Attachment1: Circuit diagram

Attachment2:
Photo, the prototype bread board

Attachment3:
Photo, the spectrum of the freq divided output. The 40MHz input has been divided into 2.4k.
There are the 3rd and 5th harmonics seen. The peak was pretty sharp but the phase noise was not evaluated yet.


The circuit was made on the prototype bread board which is apparently unsuitable for RF purposes.
Indeed, it was surprising to see its working up to 40MHz...

In order to increase the maximum freq of the system we need the following considerations

  • RF PCB board
  • Input RF buffer (or amplifier) with a 50Ohm input impedance.
  • Faster comparator. LT1016 has the response time of 10ns, which is not enough fast.
  • Faster counter. Faster chip 74HC4020 has already been ordered.
Attachment 1: freq_divider.pdf  34 kB  | Hide | Hide all | Show all
freq_divider.pdf
Attachment 2: IMG_3813.jpg  277 kB  | Hide | Hide all | Show all
IMG_3813.jpg
Attachment 3: IMG_3814.jpg  132 kB  | Show | Hide all | Show all
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