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New quantum receiver the first to detect entire radio frequency spectrum

phys.org

41–50 of 79 posts

Re: New quantum receiver the first to detect entire radio frequency spectrum

#41
post #35

Earlier quoted context omitted.

Once you have performed the sampling, or even before that technically, information theory provides the connection between the analogue and the digital. > That said most signal processing scopes at high frequencies are analogue I think the state of the art is DC to a few (10s?) GHz with direct sampling, impressive stuff.

By direct sampling do you mean non-interleaved? The UXR oscilloscope he linked has a set of 256 Gsample/sec digitizers which can do the full DC to 110GHz on all 4 channels.

Clearly I'm not up to speed then - although I had in mind one I might one day be able to buy myself as opposed to be the absolute tail end of T&M equipment worth selling.

Re: New quantum receiver the first to detect entire radio frequency spectrum

#42
post #3

Miniaturization and ruggedization for practical applications will require a lot of work. Not only are the atoms contained in a heated tube, but, unlike atomic clocks, sophisticated tunable laser technology must also be employed. So only very high value missions, like large satellites or ground installations are practicable.

How much different would the laser tech need to be than what is used today in laser gyros?

Based on how these things tend to advance I would probably give it a decade before this can fit into an ELINT pod.

Re: New quantum receiver the first to detect entire radio frequency spectrum

#43
post #41

Earlier quoted context omitted.

By direct sampling do you mean non-interleaved? The UXR oscilloscope he linked has a set of 256 Gsample/sec digitizers which can do the full DC to 110GHz on all 4 channels.

Clearly I'm not up to speed then - although I had in mind one I might one day be able to buy myself as opposed to be the absolute tail end of T&M equipment worth selling.

Yeah that scope alone costs over $1M, the probes for it probably cost more than what most people would or could pay for their house.

Re: New quantum receiver the first to detect entire radio frequency spectrum

#45
post #36

Earlier quoted context omitted.

No, it does so because of solid state tuners, and RF switches.

The article I linked claims: A fractal antenna's response differs markedly from traditional antenna designs, in that it is capable of operating with good-to-excellent performance at many different frequencies simultaneously. Is this inaccurate? The associated electronics are obviously necessary too.

Fractal antennas are mostly snake oil. You’ll always see then driven against a large counterpoise (ground plane), as the counterpoise becomes the radiator. You can make use of Chu’s limit without resorting to fractals.

https://en.m.wikipedia.org/wiki/Chu–Harrington_limit

Re: New quantum receiver the first to detect entire radio frequency spectrum

#46
This article got me interested to learn more. There's a related phenomenon called the Rydberg Blockade[1], wherein a group of Rydberg atoms can be tuned to multiple quantum states and because of their large radii, form a coverage area over space in which those quantum states are excluded for other particles (by Pauli exclusion?). There's work to create large arrays, 1D and 2D of tens to hundreds of elements, of Rydberg atoms with packed configurations that can be continuously replenished atom-by-atom. This bit is being used for optical coupling in quantum computing[2].

But this got me wondering... does this mean that such a 2D array of Rydberg atoms, continually replenished, could effectively operate as an energy capturing force field? I'm imagining a surface that for a given maintenance energy is minimally dense while maximally extensive in space, and medium duration (the Rydberg excitations last longer the more they're pumped, e.g. micro and milliseconds). Also because of the dipole coupling and high-frequency tunability (~100s of atoms in packed arrays If so, this seems to present a candidate for energy capture from photonic emissions in e.g. fusion reactions, but crucially, one that could be maintained without large amounts of mass or that mass ablating away. That might make a handy energy shield for a spaceship fusion engine (I believe that's a key problem for small fusion engine designs), esp if you could recycle the captured energy :)

[1] https://blogs.unimelb.edu.au/atomopt/rydberg-atoms/ [2] Quantum Simulators and Processors Based on Rydberg Atom Arrays https://www.youtube.com/watch?v=7MXIVZLaCII

Re: New quantum receiver the first to detect entire radio frequency spectrum

#47

Maybe it's just me, but this reads to me is as a big load of cleverly worded (misleading) statements that say little, yet make all kind of vague suggestions. I don't know any details about this particular tech, but I think the article says this can detect radio waves over a relatively large spectrum (0Hz..20GHz) simultaneously. It doesn't mention anything about focusing on any particular frequency, or even if it can…

Did you read the paper?

https://arxiv.org/pdf/2009.14383.pdf

Re: New quantum receiver the first to detect entire radio frequency spectrum

#48

Maybe it's just me, but this reads to me is as a big load of cleverly worded (misleading) statements that say little, yet make all kind of vague suggestions. I don't know any details about this particular tech, but I think the article says this can detect radio waves over a relatively large spectrum (0Hz..20GHz) simultaneously. It doesn't mention anything about focusing on any particular frequency, or even if it can…

This is a bit cynical, but a great rant and it makes some good points. I’m curious what’s your opinion on Bitcoin?

Re: New quantum receiver the first to detect entire radio frequency spectrum

#49

Maybe it's just me, but this reads to me is as a big load of cleverly worded (misleading) statements that say little, yet make all kind of vague suggestions. I don't know any details about this particular tech, but I think the article says this can detect radio waves over a relatively large spectrum (0Hz..20GHz) simultaneously. It doesn't mention anything about focusing on any particular frequency, or even if it can…

It's not an antenna like I thought at first. It's a tuner with 4 MHz instantaneous bandwidth and a very wide tuning range, https://arxiv.org/abs/2009.14383 - the actual (laser intensity) measurements are done within the RF electrical field above a coplanar waveguide track on a PCB.

It's a cool RF tuner. But it still need a real, full size, antenna. It's also not clear to me if they can get the phase informations out of the laser intensity measurements. I suppose it's all a matter of how fast they can sample the light.

Re: New quantum receiver the first to detect entire radio frequency spectrum

#50

Maybe it's just me, but this reads to me is as a big load of cleverly worded (misleading) statements that say little, yet make all kind of vague suggestions. I don't know any details about this particular tech, but I think the article says this can detect radio waves over a relatively large spectrum (0Hz..20GHz) simultaneously. It doesn't mention anything about focusing on any particular frequency, or even if it can…

It's not an antenna like I thought at first. It's a tuner with 4 MHz instantaneous bandwidth and a very wide tuning range, https://arxiv.org/abs/2009.14383 - the actual (laser intensity) measurements are done within the RF electrical field above a coplanar waveguide track on a PCB. It's a cool RF tuner. But it still need a real, full size, antenna. It's also not clear to me if they can get the phase informations out…

So basically, 3x higher than an hackrf (1MHz-~6GHz)? Not bad, but also not something revolutionary.
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