Dielectric Rod Antenna: Can It Radiate?

In summary, a dielectric material can be used as a radiating antenna because it is partially transparent to radio waves.
  • #36
Baluncore said:
What is all this sinusoidal stuff with λ and 2π ? Ever since Sir Oliver Lodge, back in 1897, wandering the gas-lit streets of London, to invent frequency tuning, we have been fighting an uphill battle to spread the spectrum.
To run me must first walk. As any waveform may be decomposed into sinusoidal components; this seems good starting point.
Prof. John Hughes made tests with a mobile receiver in 1879 in Portland Place, London. I am not aware he insisted on sine waves for his test as he was using damped waves from a spark gap and induction coil. I am not aware of Oliver Lodge doing the same.
The concept of frequency tuning was proposed by Marconi in 1901 in his famous UK 7777 patent.
 
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  • #37
tech99 said:
To run me must first walk. As any waveform may be decomposed into sinusoidal components; this seems good starting point.
That is OK, until you try to make a broadband quarter wave transformer for many different sinewaves.

tech99 said:
The concept of frequency tuning was proposed by Marconi in 1901 in his famous UK 7777 patent.
Marconi stole everything from everywhere to make a system that worked. He took out patents on inventor's techniques to stop others commercialising them.

tech99 said:
Prof. John Hughes made tests with a mobile receiver in 1879 in Portland Place, London.
I think you are referring not to John, but to David Edward Hughes, Professor of Music, discoverer of the bad electrical contact, and inventor of the microphone, & etc.

Prof. Oliver Lodge improved the sensitivity of the coherer by tuning the receiving circuit to the natural frequency of the spark transmitter. Wikipedia says; “In 1898 he was awarded the "syntonic" (or tuning) patent by the United States Patent Office”.
Edit:
GB Patent said:
No. 11,575 A.D. 1897
Date of Application, 10th May, 1897
Complete Specification Left, 5th Feb., 1898 Accepted, 10th Aug., 1898
PROVISIONAL SPECIFICATION.
Improvements in Syntonised Telegraphy without Line Wires.
I, Oliver Joseph Lodge, D.Sc., F.R.S.; of 2, Grove Park, Liverpool, in the County of Lancaster, Professor of Physics, do hereby declare the nature of this invention to be as follows :–
The object of my invention is to enable an operator to transmit messages across space to anyone or more of a number of different individuals in various localities, each of whom is provided with a suitably arranged receiver.
The method consists in utilising certain processes and apparatus for the purpose of producing and detecting rapid electric oscillations, and in so arranging them that the excitation of a particular frequency of oscillation at the sending station may cause a Morse or any other telegraphic instrument to respond at a distant station, by reason of being associated, through a relay or otherwise, with a subsidiary circuit actuated by electric oscillations of that same particular frequency, or by some multiple or sub-multiple of that frequency. Another distant station will similarly be made to receive messages by exciting at the sending station alternations of a different frequency, and so on: and thus individual messages can be transmitted to individual stations without disturbing the receiving appliances at other stations which are tuned or timed or syntonised to a different frequency. Each station will usually be provided with both sending and receiving apparatus, and messages can travel simultaneously in opposite or in cross directions without the least confusion or interference. ...

https://worldwide.espacenet.com/pub...=GB&NR=189711575A&KC=A&rnd=1530989643124&FT=D#
 
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