www.RADIONDISTICS.com

Nuclear? No, thanks! - Nucleare? No, grazie!

Planning a trip to Sicily? Then, make sure you won't be feeding the Mafia!

Pizzo-free travel - brought to you by the ADDIO PIZZO's guys
Home versione italiana Scientific Products RF Communications Products Contact

If you have a scientific interest in the physics of the radio, you should browse this site as an e-book!

Errante's 225 Ohm, MULTIBAND HF ANTENNA SYSTEM

HF Turnstile antennas broadband driver, NOW available as standard!

An axonometric view of the balun balun for our multibanda antenna system balun for our multibanda antenna system balun for turnstile antennas

NB. Our radio-communications purpose baluns can be found here.

ERRANTE's BALUN

Virtual ground balun for folded dipole & loop antennas

A state-of-the-art high power broadband HF balun

Patent n.0001347486 (ITAPA20030021)
Visit www.uibm.gov.it and enter Francesco Errante in the search box to see all of my patents, or verify it directly from the European Patent Office archive HERE !

A VIRTUAL GROUND BALUN FOR DOUBLING THE WAVELENGTH FOLDED DIPOLE ANTENNA

by Francesco Errante

Please, pay ATTENTION! This page relates to a special applicazione for scientific purposes of the Errante's virtual ground balun. To find out more on Errante's virtual ground baluns for HF radio communications and its theory click here.

Scientific purposes

a. The VIRTUAL GROUND RF BALUN TRANSFORMER described hereby allows the doubling of the wavelength folded dipole's radiator.

b. The virtual ground RF balun transformer described hereby allows to demonstrate that in a wavelength folded dipole antenna, its radiator (having a characteristic impedance of 300 ohm) acts as it was made of two distinct radiators, identical to each other and coinciding with each other, while being fed in a counterphase arrangement, having each of them a characteristic impedance of 150 Ohm, referred to the virtual ground node.

c. The virtual ground RF balun transformer described hereby allows to demonstrate that the wavelength folded dipole radiator and, indeed, any other resonant loop, be it made of any shape, with both a single turn or a multiple turn winding, when it is correctly fed with a sinusoidal radio-electric signal of a proper wavelength, it is always interested by electric currents that flow along its entire length from one end to the other in a clockwise direction for a semi-period and anti-clockwise during the next semi-period or viceversa.

Circuit description

The Author, by means of a particular radio-electric circuitry for the suppression of any which one of the two branches of a of wavelength open dipole, has previously demonstrated that it is, indeed, possible to feed each of the two branches of an wavelength open dipole independently, so that they can become electrically independent from each other allowing, therefore, to suppress any which one of them without repercussions on the condition of resonance and radiation of the remaining one. On that occasion, the Author has introduced the reader to the concept and the method for generating a virtual ground node for the separation of the dipole's branch currents.
The wavelength folded dipole antenna has a single wiring radiator and, therefore, does not allow the independent usage of the currents flowing on it, both in a clockwise and anti clockwise way.
The present invention allows to split up the folded dipole radiator into two nearly-coinciding wirings in order to demonstrate that the single folded dipole radiator acts as if it was made of two identical but distinct wirings coinciding with each other and each working cyclically for the duration of a semi-period.
This result has been achieved by means of a lumped-constants radio-electric circuit, based around a broad-band flux-coupled radio electric balun transformer(1) winded on a binocular type ferrite core having a primary winding(2) exhibiting an impedance value equal the one of the transmission line(10) being used and a center-tapped secondary winding(3) exhibiting an impedance value of 150 + 150 Ohm.
The said impedance values are referred to the virtual ground node(4 & 6). (a virtual ground node is defined as a point in an electrical circuit that appears to be at ground, but is not actually attached to ground, it is therefore, a node having a 0 degree phase angle difference with respect to ground and has the same electrical potential as the Earth)
The virtual ground node is made available to the whole circuit by means of a very short electrical connection(6) between the transformer center-tapping(4) and the balun chassis(5).
The transformer's working point is optimized by compensation with the employment of high-voltage RF duty capacitors(9).

Errante's virtual ground balun for doubling the  wavelength folded dipole antenna

It is important to highlight the fact that the two independently fed branches(7 & 8) can also be independently rotated around their common axis to give a variable radiation pattern which ranges from a typical dipole's radiation pattern, if the arms are parallel to each other or a quasi-omnidirectional radiation pattern in the case of the arms being placed perpendicularly to each-other (turnstile arrangement).

The balun described hereby is characterized by being a NON fluctuating impedance RF electrical transformer. All of its terminations impedance values are set by design, hence the impedance transformation ratio is a function of them and not viceversa, unlike it happens with any other balun arrangement.

Please, pay ATTENTION! This page relates to a special applicazione for scientific purposes of the Errante's virtual ground balun. To find out more on Errante's virtual ground baluns for HF radio communications and its theory click here.

All the concepts, methods, designs and devices presented on this web site
are the original novelty works of FRANCESCO ERRANTE.
Patents & Copyright © 2003- of FRANCESCO ERRANTE.

Material is governed by the Copyright, Designs and Patent Act.
No reproduction, in whole or in part, without written permission.
Copies of these documents made by electronic or mechanical means, including information storage and retrieval systems, may only be employed for personal use.
All rights reserved.


All rights reserved. Copyright © 2003- Francesco Errante
www.Radiondistics.com - Tel.(+39) 339.180.1313