Re: How to generate a tracking pulse with nano-seconds precision in a low-cost way

Hello Johnson,

Last month I designed a small circuit to generate the reference pulse
sequence at 35.42MHz with DW9255 (35.42M central freq plus max 300ns
GDR)at board. Now I want to add a few more components to the board so I
can generate a tracking pulse sequence as well. I want the tracking
pulse sequence is only a few nano-seconds delay compared to the
inputing pulse sequence, and I want the delay between them is as stable
as possible. For example, 10 nanoseconds delay with 1 nanosecond drms.
In other word, I only care about the time difference stability between
these two sequences.


Usually this is done with LC delay lines. Several mfgs, in North America for example:
http://www.belfuse.com/

You can, of course, roll your own. The trick for a jitter free ride is to not introduce too much low pass characteristic, maintain a nice flat group delay and follow it up with a low noise RF amp. I usually follow up with a discrete amp, BFS17 or womething like that. Or a fast buffer if digital.

Regards, Joerg

http://www.analogconsultants.com
.