Page 4 of 4 FirstFirst ... 234
Results 31 to 39 of 39

Thread: New chip claims multi-gigabit transfers over 60GHz RF

  1. #31
    Very good friend of the forum Virchanza's Avatar
    Join Date
    Jan 2010
    Posts
    863

    Default

    Quote Originally Posted by Thorn View Post
    The rule is: the higher the frequency, the higher the bandwidth, but the lower the distance the information will be transmitted. The inverse is also true.
    I've always thought that that doesn't make sense. You hear about how higher frequency waves such as X waves and Gamma rays are more penetrative (e.g. you need an inch of solid lead to stop an x-ray), so that would suggest to me that the higher frequency waves would go further...
    Ask questions on the open forums, that way everybody benefits from the solution, and everybody can be corrected when they make mistakes. Don't send me private messages asking questions that should be asked on the open forums, I won't respond. I decline all "Friend Requests".

  2. #32
    Very good friend of the forum Virchanza's Avatar
    Join Date
    Jan 2010
    Posts
    863

    Default

    Quote Originally Posted by compaq View Post
    If you had a 10kw signal at 60ghz, would that affect other signals from 5ghz down if they were in range?
    Depends entirely on the quality of the filters you use. If you had the theoretical "brick-wall filter", the yes it would work. But I don't think it should be hard to find a filter to separate 5 GHz from 60 GHz even if the 60 GHz signal is particularly powerful.
    Ask questions on the open forums, that way everybody benefits from the solution, and everybody can be corrected when they make mistakes. Don't send me private messages asking questions that should be asked on the open forums, I won't respond. I decline all "Friend Requests".

  3. #33
    Senior Member Thorn's Avatar
    Join Date
    Jan 2010
    Location
    The Green Dome
    Posts
    1,509

    Default

    Quote Originally Posted by Virchanza View Post
    Depends entirely on the quality of the filters you use. If you had the theoretical "brick-wall filter", the yes it would work. But I don't think it should be hard to find a filter to separate 5 GHz from 60 GHz even if the 60 GHz signal is particularly powerful.
    At 10kw at the distance they are talking about here (less than 5m) nothing would be working. Filters or not. Of course, I don't know where you'd find someone stupid enough to have a 10kw radiator in around their TV in the first place, so the whole point it moot.
    Thorn
    Stop the TSA now! Boycott the airlines.

  4. #34
    Very good friend of the forum killadaninja's Avatar
    Join Date
    Oct 2007
    Location
    London, United Kingdom.
    Posts
    526

    Default

    Quote Originally Posted by Virchanza View Post
    I've always thought that that doesn't make sense. You hear about how higher frequency waves such as X waves and Gamma rays are more penetrative (e.g. you need an inch of solid lead to stop an x-ray), so that would suggest to me that the higher frequency waves would go further...
    No, take high frequency/power lasers for example yes they can burn holes in steel but they cant travel no further than a lower powered (lower frequency) laser, think for example If you was ten feet away from an x-ray machine it would not work no more, because of its higher frequency it is doing more work than a lower frequency wave of the same amplitude basicaly it is oscillating more quickly.
    There for, for a higer frequency and a lower frequency to travel the same distance, what do you think will need more power?
    However I am no expert but I believe Thorn is, so on his advice im running for the hills. EDIT There is a big satelite on the hill (running in another direction)
    Sometimes I try to fit a 16-character string into an 8–byte space, on purpose.

  5. #35
    Senior Member streaker69's Avatar
    Join Date
    Jan 2010
    Location
    Virginville, BlueBall, Bird In Hand, Intercourse, Paradise, PA
    Posts
    3,535

    Default

    Quote Originally Posted by killadaninja View Post
    No, take high frequency/power lasers for example yes they can burn holes in steel but they cant travel no further than a lower powered (lower frequency) laser, think for example If you was ten feet away from an x-ray machine it would not work no more, because of its higher frequency it is doing more work than a lower frequency wave of the same amplitude basicaly it is oscillating more quickly.
    There for, for a higer frequency and a lower frequency to travel the same distance, what do you think will need more power?
    However I am no expert but I believe Thorn is, so on his advice im running for the hills. EDIT There is a big satelite on the hill (running in another direction)
    The rule of thumb in RF transmission is to double your distance, you have to square your power.

    So if you're transmitting 3W and going 2Miles, to go 4Miles, you'd have to output 9W. This is a rough way to calculate what power you'd need, and is assuming a 1.1:1 VSWR on a unity gain antenna in perfect atmospheric conditions.
    A third party security audit is the IT equivalent of a colonoscopy. It's long, intrusive, very uncomfortable, and when it's done, you'll have seen things you really didn't want to see, and you'll never forget that you've had one.

  6. #36
    Very good friend of the forum killadaninja's Avatar
    Join Date
    Oct 2007
    Location
    London, United Kingdom.
    Posts
    526

    Default

    so 5 miles 81w?
    Well the generators that power x-ray machines are in the 50-60kw mark I think, So lets say you have a perfect image at 10 inches, to get that same resolution at 20 inches with replicated conditions and the same machine (presuming the technology is capable {50kwx50kw} 2500kw? Is this how it would work or do you think the technology behind x-ray machines are slightly different.
    Sometimes I try to fit a 16-character string into an 8–byte space, on purpose.

  7. #37
    Senior Member streaker69's Avatar
    Join Date
    Jan 2010
    Location
    Virginville, BlueBall, Bird In Hand, Intercourse, Paradise, PA
    Posts
    3,535

    Default

    Quote Originally Posted by killadaninja View Post
    so 5 miles 81w?
    No. Recheck your math.

    2M = 3W
    4M = 9W
    8M = 81W

    ...and so on. As I said, these are rough calculations, but it's a good way to determine how much power you'd need for a certain distance, and it can vary a bit with frequency.
    A third party security audit is the IT equivalent of a colonoscopy. It's long, intrusive, very uncomfortable, and when it's done, you'll have seen things you really didn't want to see, and you'll never forget that you've had one.

  8. #38
    Very good friend of the forum killadaninja's Avatar
    Join Date
    Oct 2007
    Location
    London, United Kingdom.
    Posts
    526

    Talking

    Woops Streaker, thats what I ment as you can see with my 10-20 inches example, I must have wrote 5 by mistake, well were not all as smart as windows vista :-D
    Sometimes I try to fit a 16-character string into an 8–byte space, on purpose.

  9. #39
    Senior Member Thorn's Avatar
    Join Date
    Jan 2010
    Location
    The Green Dome
    Posts
    1,509

    Default

    Quote Originally Posted by Virchanza View Post
    I've always thought that that doesn't make sense. You hear about how higher frequency waves such as X waves and Gamma rays are more penetrative (e.g. you need an inch of solid lead to stop an x-ray), so that would suggest to me that the higher frequency waves would go further...
    Sorry, I missed this before.

    It may not makes sense, but that is the way it works. You're confusing a couple of things. First is what a given wave will penetrate, verses the distance they will travel. RF waves will actually penetrate a lot of stuff (and over long distances), but they can be blocked by things that have the proper resonance for the wavelength. Think of getting an FM broadcast: In a wooden home, it's usually very easy, but in a steel lattice bridge, it can be difficult. The FM waves penetrate the wood and plaster, etc., without any effort, but are blocked by the steel lattice frame, even though it have huge openings in it. The frame resonates in the correct frequencies, and the openings in the framework are actually too small to allow the FM waves to pass.

    The second thing is that when you get into the ionizing radiation (X and Gamma rays, etc.), the rules change a lot. This is because of the ionization, the process whereby electrons get either knocked off or added to an atom.

    Going back to frequency and distance, you can see the rule about "higher the frequency, the higher the bandwidth but the lower the distance the information will be transmitted" around you in every day examples. Two very common examples that most people here would know are commercial FM (89MHz-107MHz) radio and WiFi (2.5GHz). Using a transmitted power output of one watt with an omnidirectional antenna in the FM band, the signal will travel about about 5 miles in a clear RF LOS, and can carry voice and music, about 50 kbps, but that's about it. In the FM signal there isn't enough bandwidth to carry much more. Using a transmitted power output of one watt with an omnidirectional antenna with WiFi, the signal be usable between devices about 0.25 miles, but it can carry a 10-50 mbps data.
    Thorn
    Stop the TSA now! Boycott the airlines.

Page 4 of 4 FirstFirst ... 234

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •