Zener diode avalanche breakdown as wideband RF transmitter

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lfarrand

Zener diode avalanche breakdown as wideband RF transmitter « on: 2022-06-09, 22:44:25 »

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Posts: 293

Ok folks, hear me out. I've read a fair amount about Don Smith's devices as well as Steven Mark's TPU, and I was reading another thread at a different forum when something clicked. Both Don Smith's and Steven Mark's devices were radio frequency transmitters and receivers. If Don Smith is to be believed (I do), then tuning into and receiving these RF signals results in tremendous usable power. I recall that Kapanadze had a strange looking toroidal wire antenna in the fish tank device, so maybe that was operating using a simiar principle. Another one is Ismael Aviso who was a RF satellite engineer and this background experience seems relevant. How did Tesla's Pierce Arrow generate power for the motor?

Now, how do we generate an RF signal? Use an antenna and pump AC into it, right? That's generally in a narrow band based on the construction of the antenna and requires a precisely constructed receiver antenna. Also requires lots of power to transmit a narrow range, whereas I think we'd like to broadcast a wide range of frequencies to make our receiving system 'auto tuning' and receive a broad spectrum of frequencies.

My idea is use the avalanche mode operation of Zener diodes as a generator of vast quantities of RF noise and then harvest electricity from the reception of these signals in appropriately designed antennas. The RF noise, being random, would naturally contain a wide range of frequencies (much like in a spark gap). This means that you wouldn't necessarily need to tune into a particular frequency and worry about 1/4 wave lengths and all that jazz.

From https://en.wikipedia.org/wiki/Avalanche_transistor:
An avalanche transistor is a bipolar junction transistor designed for operation in the region of its collector-current/collector-to-emitter voltage characteristics beyond the collector-to-emitter breakdown voltage, called avalanche breakdown region. This region is characterized by avalanche breakdown, which is a phenomenon similar to Townsend discharge for gases, and negative differential resistance. Operation in the avalanche breakdown region is called avalanche-mode operation: it gives avalanche transistors the ability to switch very high currents with less than a nanosecond rise and fall times (transition times). Transistors not specifically designed for the purpose can have reasonably consistent avalanche properties; for example 82% of samples of the 15V high-speed switch 2N2369, manufactured over a 12-year period, were capable of generating avalanche breakdown pulses with rise time of 350 ps or less, using a 90V power supply as Jim Williams writes.

From https://en.wikipedia.org/wiki/Townsend_discharge:
The Townsend discharge or Townsend avalanche is a gas ionisation process where free electrons are accelerated by an electric field, collide with gas molecules, and consequently free additional electrons. Those electrons are in turn accelerated and free additional electrons. The result is an avalanche multiplication that permits electrical conduction through the gas. The discharge requires a source of free electrons and a significant electric field; without both, the phenomenon does not occur.

From https://www.electronics-notes.com/articles/basic_concepts/electronic-rf-noise/avalanche-noise-what-is.php:
Avalanche diodes generate large quantities of radio frequency noise. As a result they are widely used noise sources for RF measurements, e.g. for RF for antenna analyser bridges and also in other items such as random number generators.

In these applications either avalanche diodes or even voltage regulator (Zener) diodes may be used. When Zener diodes are used, the diodes must have breakdown voltages above about 5.5 volts because diodes with voltages above this value chiefly use avalanche breakdown, below this value Zener breakdown is the chief mode.

I'm going to test my hypothesis by driving a Zener diode in avalanche mode and seeing if I can 'receive' the signal using some litz wire.

lfarrand	Re: Zener diode avalanche breakdown as wideband RF transmitter « Reply #1 on: 2022-06-09, 23:03:29 »
Sr. Member Posts: 293	Will also require use of a high permeability core. Luckily I have some Metglas cores to hand.

Grumpy	Re: Zener diode avalanche breakdown as wideband RF transmitter « Reply #2 on: 2022-06-11, 01:21:28 »
Group: Tinkerer Hero Member Posts: 4265 tExB=qr	What you propose offers no mechanism for gain or conversion from an energy source.

F6FLT

Re: Zener diode avalanche breakdown as wideband RF transmitter « Reply #3 on: 2022-06-13, 10:02:11 »

Group: Professor
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Posts: 2519

Quote from: lfarrand on 2022-06-09, 22:44:25

...
My idea is use the avalanche mode operation of Zener diodes as a generator of vast quantities of RF noise and then harvest electricity from the reception of these signals in appropriately designed antennas.
...

You'll get almost nothing back. First, the generation of electromagnetic waves is always done with losses in the resistive part of the generator output impedance (here, the diode), then there will be additional losses between the transmitting and receiving antennas due to imperfect coupling, finally there is no reason to believe that the noise power generated by the diode would be higher than the one needed to feed it. Or would you have some that generations of electronic engineers before you would not have seen? And why?

Electromagnetic radiation is generated by the acceleration of electrons in an antenna, thus by a high frequency electric current. In reception, it is the opposite, the field induces in the antenna the acceleration of the electrons, thus generates a current. As we already have the high frequency current in the diode, it is completely absurd to go through an intermediate antenna coupling to recover only a part of it.

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