A Metal sheet of limited dimensions, say an aluminium foil (oven foil) would be able to support a ZN power transmission of upto 66%-20% efficiency between a range of 2.7m to 15m.
A metal sheet of limited dimensions, say an aluminium foil (oven foil), would also be able to support a DC current transmission of upto 66%-20% efficiency between a range of 2.7m to 15m. What's the point?
And what does it tell us about the validity of the concept to transmit waves across the inhomogeneous, much less conducting, corrugated surface of the Earth, over distances many orders of magnitude larger?
Interesting. But the point here is that coupled WPT systems do not support multi receiver power up with the same efficiency as they do for single receiver.
1. The peak splitting happens
2. Misalignment of Tx and Rx takes a massive toll
3. Partial metal shields such as ships, shipping containers, industrial pipelines etc hinder EM based Power transfer due to Faraday shielding or EM shielding effect.
So, to counter the above issues, one simple way is to get rid of "coupled" and "radiation" element in the transmission, altogether. Therefore, a wave based solution is desirable.
As far as validity is concerned,
1. The ZW equi-phases sink into the lossy dielectric media[1]-[8]. The system I developed shows that property. See the figures attached[in my previous responses], where an ANSYS HFSS simulation of the same shows this property.
2. The ZW specifically exhibits evanescent field decay property [1]-[9].
3. The slow attenuation rate of Ez(Y) component of the field[1]-[8].
If the said company's system exhibits all the above properties, then it is indeed a ZW system, else, it is at the best a Single Wire Power Transfer system.
DC Transmission:
The point here is, you can always use a cable to transmit power, but then, WPT was all about reducing the wire involved. If one looks at Tesla's earliest patent of 1900, he wasn't referring to a "wireless" but a "less-wire" system and hence the concept of single wire transmission came up. e.g. Goubau line.
The entire point of research with proper scientific rigor is to increase the range of transmission, to see an advantage over DC. One key point is to go below 1MHz range to increase the distance. Unfortunately, the half-wave resonator system would become large. Earth is an inhomogeneous media, however at lower frequencies is acts as a conductor a fact well noted by Schelkunoff, Barlow and Sarkar et.al[1]-[3].
I donot want to conclude anything specific here, but, am open to do a research on this. There might be a caveat somewhere, which needs to be explored.
Corrugated SurfaceThey are known to support Surface waves, ZW may be not that much. But, then ZW, Surface waves and Surface Plasmons are all classified in the same category.
PS: I ran out of space at my lab to experiment beyond 15m. Also the largest ship container Hyundai Heavy Industry(HHI) threw at me was 14.83m, thats the High-Q container we are talking about. The thickest metal they sent me was 80 mm, used for hull at HHI. I built a radio system for voice communication, based on the above concept, which covers multiple decks without the use of a repeater or relay[320 m range, LNG carrier ship and Dolphin semisub oil rig]. This is not possible for a mono-pole motorola system, unless a relay or repeater is used.References
1. S. Schelkunoff, IRE Trans. on Antenna and Propagation 7, 133-139 (1959)
2. T. K. Sarkar, M. N. Abdallah, M. Salazar-Palma and W.M. Dyab, IEEE Antennas
and Propagation Magazine 59, 77-93(2017).
3. H.M. Barlow, and A.L. Cullen, Proceed. of the IEE - Part III: Radio and Comm.
Engineering 100, 329-341 (1953).
4. Zenneck, J. Uber die Fortpflanzung ebener elektromagnetischer Wellen l¨angs einer ¨
ebenen Leiterfl¨ache und ihre Beziehung zur drahtlosen Telegraphie. Ann. d. Phys. 23,
846-866 (1907).
5. Sommerfeld, A. N. Uber die Ausbreitung der Wellen in der drahtlosen Telegraphie. ¨
Ann. d. Phys. 28, 665-736(1909).
6. Jangal,F., Bourey, N., Darces, M., Issac, F. & H´elier, M. Observation of Zenneck-Like
Waves over a Metasurface Designed for Launching HF Radar Surface Wave. Hindawi,
International J. of Antennas and Propagation 2016,1 (2016).
7. Jeon,T.I., Zhang, J., & Grischkowsky, D. THz Zenneck surface wave (THz surface
plasmon) propagation on a metal sheet. Appl. Phys. Lett. 86, 161904 (2005).
8. Goubau,G. Surface Waves and Their Application to Transmission Lines. Journal of
Appl. Physics 21, 1119(1950).
9. S.K. Oruganti, O. Kaiyrakhmet and F. Bien, URSI Asia-Pacific Radio Science Conference, 318(2016).