Re: [time-nuts] Sub-ps delay line

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

Re: [time-nuts] Sub-ps delay line

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

Re: [time-nuts] Sub-ps delay line

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

Re: [time-nuts] Sub-ps delay line

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

Re: [time-nuts] Sub-ps delay line

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

Re: [time-nuts] Sub-ps delay line

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

Re: [time-nuts] Sub-ps delay line

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

Re: [time-nuts] Sub-ps delay line

 -AE6RV.com GFS GPSDO list: groups.yahoo.com/neo/groups/GFS-GPSDOs/info From: Mattia Rizzi <mattia.ri...@gmail.com> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> Sent: Tuesday, February 7, 2017 10:13 AM Subject: [time-nuts] Sub-p

Re: [time-nuts] Sub-ps delay line

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

Re: [time-nuts] Sub-ps delay line

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:

Re: [time-nuts] Sub-ps delay line

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

[time-nuts] Sub-ps delay line

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