ERRANTE's
CAPACITIVE RF EARTH GROUNDING
SYSTEM
Say goodbye to the ground
plane!
How to correctly polarize an
unbalanced RF system with reference to the physical ground.
This system demonstrates that
no galvanic coupling to earth is needed for a proper RF earth
grounding.
Errante's capacitive RF earth
grounding system
by Francesco Errante
Further to what I have previously disclosed and
demonstrated in the matter of grounding systems for the radio-electric
transdusers and transmission lines for radio-electric signals, I am hereby
disclosing and demonstrating that NO galvanic path to earth is needed for the
proper polarization of an un-balanced RF system with reference to the
physical ground. ALL IT TAKES IS A LARGE ENOUGH lumped CAPACITANCE yelding a
very low capacitive reactance (<0.5% of the radiator own impedance) at the
lowest operating frequency of a given RF un-balanced system, as shown in the
picture below:
Errante's CAPACITIVE RF EARTH GROUNDING SYSTEM
schematic diagram.
An unbalanced radiator and its Un-Un impedance transformer being grounded to
the earth by means of a capacitive plate (P) coupled through a dielectric layer
to the physical ground - Copyright © 2009 - Francesco Errante
Errante's ONE-WIRE UNBALANCED RF TRANSMISSION LINE,
employing Errante's CAPACITIVE RF EARTH GROUNDING SYSTEM - Copyright © 2009 -
Francesco Errante
The grounding capacitance is
obtained by coupling the point of a radio-electric circuit that needs to be
at a 0 Volt reference, directly to the ground by means of a metallic plate
(P) facing a uniform plot of ground surface and isolated
from it by a properly sized dielectric layer, as shown in the picture above.
(NOT through a capacitor of equal value!!! Even Guglielmo
Marconi made this mistake as documented in his Nobel
lecture)
In the medium, long and very long waves spectrum, in order to increase the
grounding capacitance value, the plate can be three-dimensional in the shape
of an hollow cube or hollow cylinder buried into the ground but isolated from
it. The volume occupied by the hollow cube or the cylinder can then be filled
with concrete and can be used as a plinth for self-radiating lattice towers.
This will also bring about huge savings in the cost of a transmitting VLF
aerial for broadcasting and military purposes.
NB. If necessary, for lightening protection the system can
also be galvanically earth grounded through an anti-inductive (RF choke)
winding connected between one edge of the capacitive plate and a ground
stake
The half a capacitor layout shown in the picture above, MUST not be
mistaken for a "ground plane" . It is easy to understand,
for example, that a metal plate of less than a square meter in size would
hardly act as a "ground plane" in a 3.5 MHz system, while it is very
effective if it is its capacitive reactance to be employed. On the contrary,
some multi-wire ground plane systems, still in use, are infact rudimental
lossy distributed capacitors.
A practical application, demonstrating this
system, can be found on the Errante's
225 Ohm, multiband HF antenna system with a capacitive
grounded Un-Un feeding system.
L or C Reactance Calculator
Enter any two known values and press "Calculate" to solve
for the others. For example, a 1 uF capacitor or a 25.3 mH inductor will have
159 Ohms of reactance at a frequency of 1000 Hertz. Fields should be reset to 0
before doing a new calculation.
Inductive Reactance (Xl) = 2 * Pi * F * L
Capacitive Reactance (Xc) = 1 / ( 2 * Pi * F * C )
Resonant Frequency (Fo) = 1 / ( 2 * Pi * SquareRoot(LC) )
Applet by Bill Bowden
© 22nd. October 1999 Bill Bowden - All rights reserved.
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