Rune Allnor <allnor@tele.ntnu.no> writes:> [...] > I can guarantee that you will find that the transients > propagate down range with a speed exactly equal to c.<chuckle> -- Randy Yates % "Midnight, on the water... Digital Signal Labs % I saw... the ocean's daughter." mailto://yates@ieee.org % 'Can't Get It Out Of My Head' http://www.digitalsignallabs.com % *El Dorado*, Electric Light Orchestra
How to get envelope from AM signal without phase shift
Started by ●March 7, 2010
Reply by ●March 22, 20102010-03-22
Reply by ●March 22, 20102010-03-22
Rune Allnor wrote:> On 22 Mar, 22:43, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de> > wrote: >> Hi Rune, >> >> What ever the the reason for this phenomina, given the known and excepted >> transfer function of a dipole source, It should be possible to transmit >> information faster than light by transmitting an AM signal in the nearfield >> and decoding the modulation. Simmulations clearly show that the envelope of >> an AM signal will arrive faster than light and undistorted in the >> nearfield. What is needed now is to find a way to decode the modulation >> within a fraction of (<1/10) a carrier cycle. > > Wrong. > > Your simulations use fixed-parameter sinusoidals and have > as such nothing to do with information, only steady states. > Everything is known all the time; there is nothing new to > be learned from observing the wave field. Hence, no > information is transmitted. > > If you want to transmit *information*, you need to change > something in the wavefield: The amplitude, the frequency > or the phase. Something that is not known, that the reciever > has to lock on to, detect and quantify. It is this *transient* > change to an *unknown* state that carries the information down > range between transmitter and reciever. > > I can guarantee that you will find that the transients > propagate down range with a speed exactly equal to c.Or perhaps slower in the near field -- certainly waves in a waveguide generally have a phase speed that's faster than c, but a group velocity that's slower. I wouldn't know if near field really is slower without doing the math, and I'd have to go back to school for a year or two to do that! Information encoded on entangled photons may or may not travel faster than light, but if they did so reliably and easily I would expect some commercial exploitation by now. -- Tim Wescott Control system and signal processing consulting www.wescottdesign.com
Reply by ●March 22, 20102010-03-22
Rune Allnor wrote:> On 22 Mar, 22:43, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de> > wrote: >> Hi Rune, >> >> What ever the the reason for this phenomina, given the known and excepted >> transfer function of a dipole source, It should be possible to transmit >> information faster than light by transmitting an AM signal in the nearfield >> and decoding the modulation. Simmulations clearly show that the envelope of >> an AM signal will arrive faster than light and undistorted in the >> nearfield. What is needed now is to find a way to decode the modulation >> within a fraction of (<1/10) a carrier cycle. > > Wrong. > > Your simulations use fixed-parameter sinusoidals and have > as such nothing to do with information, only steady states. > Everything is known all the time; there is nothing new to > be learned from observing the wave field. Hence, no > information is transmitted. > > If you want to transmit *information*, you need to change > something in the wavefield: The amplitude, the frequency > or the phase. Something that is not known, that the reciever > has to lock on to, detect and quantify. It is this *transient* > change to an *unknown* state that carries the information down > range between transmitter and reciever. > > I can guarantee that you will find that the transients > propagate down range with a speed exactly equal to c.Not necessarily that fast. Note that in waveguides, the product of phase ans group velocities is c^2. At cutoff, the group velocity drops to zero and the phase velocity becomes infinite. The energy travels transversely (cross the axis of the guide) giving infinite phase velocity like a wave straight onto a beach, so there is no energy traveling along the axis, making the group velocity zero. Jerry -- Discovery consists of seeing what everybody has seen, and thinking what nobody has thought. .. Albert Szent-Gyorgi �����������������������������������������������������������������������
Reply by ●March 22, 20102010-03-22
I dissagree. Simulation results show that if you add two signals with different frequencies and differnt amplitudes, the resultant signal changes in a random way as far as a detector is concerned. If the signal is modulated with a carrier and transmitted by a dipole antenna to another dipole antenna in the nearfield, the envelope of the received signal arrives undistorted, faster than light. This is because for a narrowband AM signal, the dispersion curve (phase and amplitude) is linear over the bandwidth of the signal. Provided the SNR is high enough, the random modulation information can then be decoded by dividing by the carrier. Comparing the transmitted modulation to the received modulation clearly shows that the modulation propagates undistorted, faster than light in the nearfield. But if a pulse is transmitted in the nearfield the pulse will distort because the dispersion curve (phase and amplitude) is not linear over the bandwidth of the signal, so group speed has no meaning in the nearfield. But in the farfield, the pulse will realign and propagate without distortion at the speed of light, so the pulse group speed only has meaning in the farfield. William>On 22 Mar, 22:43, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de> >wrote: >> Hi Rune, >> >> What ever the the reason for this phenomina, given the known andexcepted>> transfer function of a dipole source, It should be possible to transmit >> information faster than light by transmitting an AM signal in thenearfield>> and decoding the modulation. Simmulations clearly show that the envelopeof>> an AM signal will arrive faster than light and undistorted in the >> nearfield. What is needed now is to find a way to decode the modulation >> within a fraction of (<1/10) a carrier cycle. > >Wrong. > >Your simulations use fixed-parameter sinusoidals and have >as such nothing to do with information, only steady states. >Everything is known all the time; there is nothing new to >be learned from observing the wave field. Hence, no >information is transmitted. > >If you want to transmit *information*, you need to change >something in the wavefield: The amplitude, the frequency >or the phase. Something that is not known, that the reciever >has to lock on to, detect and quantify. It is this *transient* >change to an *unknown* state that carries the information down >range between transmitter and reciever. > >I can guarantee that you will find that the transients >propagate down range with a speed exactly equal to c. > >Rune >
Reply by ●March 22, 20102010-03-22
Randy Yates wrote:> Rune Allnor <allnor@tele.ntnu.no> writes: > >>[...] >>I can guarantee that you will find that the transients >>propagate down range with a speed exactly equal to c. > > > <chuckle>It looks like there is more and more of them every day. Scarry. VLV
Reply by ●March 23, 20102010-03-23
On 3/22/2010 5:12 PM, WWalker wrote:> I dissagree. > > Simulation results show that if you add two signals with different > frequencies and differnt amplitudes, the resultant signal changes in a > random way as far as a detector is concerned. If the signal is modulated > with a carrier and transmitted by a dipole antenna to another dipole > antenna in the nearfield, the envelope of the received signal arrives > undistorted, faster than light. This is because for a narrowband AM signal, > the dispersion curve (phase and amplitude) is linear over the bandwidth of > the signal. Provided the SNR is high enough, the random modulation > information can then be decoded by dividing by the carrier. Comparing the > transmitted modulation to the received modulation clearly shows that the > modulation propagates undistorted, faster than light in the nearfield. > > But if a pulse is transmitted in the nearfield the pulse will distort > because the dispersion curve (phase and amplitude) is not linear over the > bandwidth of the signal, so group speed has no meaning in the nearfield. > But in the farfield, the pulse will realign and propagate without > distortion at the speed of light, so the pulse group speed only has meaning > in the farfield. > > WilliamMixing top and bottom posting is very bad form and makes your responses difficult to read, or at least very difficult to sort out the logic train you're responding to. So what carries the information faster than light? Clearly it can't be an EM photon, since they're inherently limited to c. If it's not via EM photons, how does the energy get from the transmit to the receive antenna?> >> On 22 Mar, 22:43, "WWalker"<william.walker@n_o_s_p_a_m.imtek.de> >> wrote: >>> Hi Rune, >>> >>> What ever the the reason for this phenomina, given the known and > excepted >>> transfer function of a dipole source, It should be possible to transmit >>> information faster than light by transmitting an AM signal in the > nearfield >>> and decoding the modulation. Simmulations clearly show that the envelope > of >>> an AM signal will arrive faster than light and undistorted in the >>> nearfield. What is needed now is to find a way to decode the modulation >>> within a fraction of (<1/10) a carrier cycle. >> >> Wrong. >> >> Your simulations use fixed-parameter sinusoidals and have >> as such nothing to do with information, only steady states. >> Everything is known all the time; there is nothing new to >> be learned from observing the wave field. Hence, no >> information is transmitted. >> >> If you want to transmit *information*, you need to change >> something in the wavefield: The amplitude, the frequency >> or the phase. Something that is not known, that the reciever >> has to lock on to, detect and quantify. It is this *transient* >> change to an *unknown* state that carries the information down >> range between transmitter and reciever. >> >> I can guarantee that you will find that the transients >> propagate down range with a speed exactly equal to c. >> >> Rune >>-- Eric Jacobsen Minister of Algorithms Abineau Communications http://www.abineau.com
Reply by ●March 23, 20102010-03-23
On 23 Mar, 01:12, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de> wrote:> I dissagree. > > Simulation results show that if you add two signals with different > frequencies and differnt amplitudes, the resultant signal changes in a > random way as far as a detector is concerned.That's the interference. In a steady-state condition. Interference is hard to quantify because it is chaotic: Make the slightest change in any of the initial conditions or environmental parameters, and it causes a total chance of the resulting interfernce pattern.> If the signal is modulated > with a carrier and transmitted by a dipole antenna to another dipole > antenna in the nearfield, the envelope of the received signal arrives > undistorted, faster than light.No, it doesn't. The amateur might have a look at the interference and get such ideas, but the professional will be aware of observations of the wave field at oblique angles from the propagation. This is a simple excercise, that can even be simulated: Start out with a 2D plane wave propagating in the x direction: s(t,x,y) = sin( 2pi f(t - x/c) ) Then observe it along a line through (0,0) that intersects the wavefield at an angle with the x axis, phi. If phi = 0, you will see an apparent wavelength, lambda', along the line that equals the free field wavelength lambda = c / f. Change the angle of the observation line, and find that the apparent wavelength equals lambda' = lambda / cos(phi) Run a simulation of how the observation changes with time, and find that the *apparent* speed c' of the wave along the observation line equals c' = lambda' f = lambda f / cos (phi) = c / cos(phi). It's a ridiculously simple trap, but it seems you have fallen into it. Rune
Reply by ●March 23, 20102010-03-23
On 23 Mar, 02:16, Vladimir Vassilevsky <nos...@nowhere.com> wrote:> Randy Yates wrote: > > Rune Allnor <all...@tele.ntnu.no> writes: > > >>[...] > >>I can guarantee that you will find that the transients > >>propagate down range with a speed exactly equal to c. > > > <chuckle> > > It looks like there is more and more of them every day. > Scarry.I don't know if you have looked at the paper he has referred to a couple of times. He claims that he at some time was affiliated with NTNU. I am not at all surprised - this kind of stuff is just what I would expect from that place. Once upon a time I asked what the procedure is to hand back my PhD diplomas etc, as I didn't want more affiliations with them than absolutely necessary. Cut as many ties as possible. It turned out there were no such procedures. So one needs to be acutely cautious about whose company one seeks - their stain might last a lifetime. Rune
Reply by ●March 23, 20102010-03-23
>On 23 Mar, 02:16, Vladimir Vassilevsky <nos...@nowhere.com> wrote: >> Randy Yates wrote: >> > Rune Allnor <all...@tele.ntnu.no> writes: >> >> >>[...] >> >>I can guarantee that you will find that the transients >> >>propagate down range with a speed exactly equal to c. >> >> > <chuckle> >> >> It looks like there is more and more of them every day. >> Scarry. > >I don't know if you have looked at the paper he has referred >to a couple of times. He claims that he at some time was >affiliated with NTNU. I am not at all surprised - this kind >of stuff is just what I would expect from that place. > >Once upon a time I asked what the procedure is to hand back >my PhD diplomas etc, as I didn't want more affiliations with >them than absolutely necessary. Cut as many ties as possible. > >It turned out there were no such procedures. So one needs to >be acutely cautious about whose company one seeks - their stain >might last a lifetime.You're being too negative. I think he's on to something, and will produce the ideal advanced communications system to showcase my new infinite gain bandwidth amplifier. Steve
Reply by ●March 23, 20102010-03-23
Rune, Your arguments do not apply. First of all the fields in the nearfield are not plane waves and secondly, the superluminal effect is observed when the antennas are pointed directly at each other (phi=0). William>On 23 Mar, 01:12, "WWalker" <william.walker@n_o_s_p_a_m.imtek.de> >wrote: >> I dissagree. >> >> Simulation results show that if you add two signals with different >> frequencies and differnt amplitudes, the resultant signal changes in a >> random way as far as a detector is concerned. > >That's the interference. In a steady-state condition. > >Interference is hard to quantify because it is chaotic: Make >the slightest change in any of the initial conditions or >environmental parameters, and it causes a total chance of the >resulting interfernce pattern. > >> If the signal is modulated >> with a carrier and transmitted by a dipole antenna to another dipole >> antenna in the nearfield, the envelope of the received signal arrives >> undistorted, faster than light. > >No, it doesn't. The amateur might have a look at the interference >and get such ideas, but the professional will be aware of >observations of the wave field at oblique angles from the >propagation. > >This is a simple excercise, that can even be simulated: > >Start out with a 2D plane wave propagating in the x direction: > >s(t,x,y) = sin( 2pi f(t - x/c) ) > >Then observe it along a line through (0,0) that intersects the >wavefield at an angle with the x axis, phi. If phi = 0, you >will see an apparent wavelength, lambda', along the line that >equals the free field wavelength lambda = c / f. > >Change the angle of the observation line, and find that >the apparent wavelength equals > >lambda' = lambda / cos(phi) > >Run a simulation of how the observation changes with time, >and find that the *apparent* speed c' of the wave along the >observation line equals > >c' = lambda' f = lambda f / cos (phi) = c / cos(phi). > >It's a ridiculously simple trap, but it seems you >have fallen into it. > >Rune >
