Have you considered an I/Q phase shifterr? Signals in RF systems are
commonly phase shifted by using an I/Q quadrature modulator. Here is
how this works:
Apply the source sinewave signal to a quadrature hybrid (or some other
network which produces two outputs with a precise 90 degree phase
relat
is it possible to run each ADC using whatever phase of the common clock you
have, measure the local phase differences between ADC's periodically, and
then work out the necessary sample offsets for the ensemble in software?
this ought to be more robust than trying to hold everything fixed over lon
If you make a variable delay by adding external RC (varicap) circuits,
the edges will be slower, and the amplitudes will be affected. This will
tend to complicate the detection and reshaping of the clock by the
LTC6957. Pay particular attention to page 24 and Fig 8 in the datasheet,
regarding t
Hello,
thank you all for the answers!
The description I gave in the first email is a simplification of the
system. The delay line is used to phase-match the clocks of a distributed
measurement system. Each board feature an ADC and a DAC. You can see it as
a distributed RF acquisition system, with
Even presuming this system is for clocking within a single-board
environment, that seems like a fairly tall order for setting resolution
and long-term stability. It could be tough to keep these numbers with
temperature and supply variations in all the circuitry involved,
including the parts tha
Hi,
My first thought would be to use a pair of couplers before and after the
delay line and bring it into a mixer to serve as a phase detector such
that you can create a control loop to stabilize delay. This way you get
a handle on the temperature variations.
There is trombone delays that ca
I did something similar a couple years ago to make an adjustable 75
nanosecond pretrigger for my sampling oscilloscope so I will just pass
along some things I learned.
Power supply noise will create jitter in single ended logic because of
lack of power supply rejection. Temperature will be a prob
-AE6RV.com
GFS GPSDO list:
groups.yahoo.com/neo/groups/GFS-GPSDOs/info
From: Mattia Rizzi
To: Discussion of precise time and frequency measurement
Sent: Tuesday, February 7, 2017 10:13 AM
Subject: [time-nuts] Sub-ps delay line
Hello,
I'm looking/designing a s
Hello,
>Put a length of coax in an adjustable oven ?
Using the numbers provided by [1], RG58 has about -0.152 ps/m/deg. I need
1 ns range, cable length is prohibitive.
cheers,
Mattia
[1] http://www.hepl.hiroshima-u.ac.jp/phx/notes/cable/cable.html
2017-02-07 18:04 GMT+01:00 Poul-Henning Kamp
In message
, Mattia Rizzi writes:
>I'm looking/designing a sub-ps delay line with very high stability.
>Basically it has microwave requirements on phase matching.
>The main features that such delay line should have are:
>- sub-ps resolution and about 1 ns range
Put a length of coax in a
I would also advise you take a look at how well you can maintain your
system impedance, say 50 Ohms. For example, I have seen about 100's ps
phase difference on a 10 MHz reference, using one BNC female-female coupler
versus another, a small part is due to TOF, but most of that is due to
subtle diff
Hello,
I'm looking/designing a sub-ps delay line with very high stability.
Basically it has microwave requirements on phase matching.
The main features that such delay line should have are:
- sub-ps resolution and about 1 ns range
- High stability, must not drift more than 2ps/year, preferably 1ps/
12 matches
Mail list logo