Antenna Axial Ratio RHCP LHCP
 

On 14 Feb, 09:55, "David G. Nagel" wrote:
art wrote:
On 13 Feb, 22:18, "Jerry Martes" wrote:
"Bobby" wrote in message

roups.com...

All,
How do you determine the axial ratio from a RHCP wave to a LHCP wave
from an antenna? In essence, I need an axial ratio transformation from
RHCP to LHCP.
Any ideas on the equation or where I can find it will be helpful.
Thanks.
Bobby.
Hi Bobby

If you are working with an antenna that radiates RHCP it is totally
insensitive to LHCP.
If you have an antenna that radiates "RHCP" (or LHCP) the axial ratio is
the ratio of the Minor axis to the Major axis of the E field. So, it
varies from zero to one as the radiated field varies from Linear to
Circular.

Jerry

You mentioned insensetivity above, are there any other polarities
insensitive to others ? I note that weather antennas are now migrating
to
dual diversity antennas for horizontal and vertical, is it possible to
totally isolate those too.?
Art

Any cross polarization situation will exhibit insensitivity to others.
For instance take a vertical antenna and a horizontal antenna at a
distance. There is a signifant reduction in signal strength.
Or take a dipole oriented NS and a dipole oriented EW and you will see a
loss of signal also.

Dave WD9BDZ- Hide quoted text -

- Show quoted text -

David, could you add to your posting some of it doesn't seem to jive.
Art

Antenna Axial Ratio RHCP LHCP
 

On 14 Feb, 11:01, "art" wrote:
On 14 Feb, 09:55, "David G. Nagel" wrote:





art wrote:
On 13 Feb, 22:18, "Jerry Martes" wrote:
"Bobby" wrote in message

roups.com...

All,
How do you determine the axial ratio from a RHCP wave to a LHCP wave
from an antenna? In essence, I need an axial ratio transformation from
RHCP to LHCP.
Any ideas on the equation or where I can find it will be helpful.
Thanks.
Bobby.
Hi Bobby

If you are working with an antenna that radiates RHCP it is totally
insensitive to LHCP.
If you have an antenna that radiates "RHCP" (or LHCP) the axial ratio is
the ratio of the Minor axis to the Major axis of the E field. So, it
varies from zero to one as the radiated field varies from Linear to
Circular.

Jerry

You mentioned insensetivity above, are there any other polarities
insensitive to others ? I note that weather antennas are now migrating
to
dual diversity antennas for horizontal and vertical, is it possible to
totally isolate those too.?
Art

Any cross polarization situation will exhibit insensitivity to others.
For instance take a vertical antenna and a horizontal antenna at a
distance. There is a signifant reduction in signal strength.
Or take a dipole oriented NS and a dipole oriented EW and you will see a
loss of signal also.

Dave WD9BDZ- Hide quoted text -

- Show quoted text -

David, could you add to your posting some of it doesn't seem to jive.
Art- Hide quoted text -

- Show quoted text -

David , maybe it was I that was not so clear.
My arials are based around a cluster of elements that are at various
placement with respect to each other tho all are resonant as is the
cluster as a whole. So when it is used for diversity operation because
more than one element is resonant choices can be made as to where to
feed to advantage
as quick as possible with a change over such that the reflection is
meaningful with respect to time. I don't believe that the weather
people radiate both at the same time as the search is for purity with
respect to polarity. In fact all the arials ive seen cannot possibly
be pure since they all seem to have elements in the vertical position
which cannot lead to purity in any form. I saw one in a antenna book
( shelnikov)where the elements were in helical form one behind the
other at a 90 degree offset but I have no further knoweledge of that
one. Somebody mentioned that some radios are now made with two ports
such that the receive portion automatically switches to the loudest
signal to overcome fading so I may well be incorrect about
simultaneous transmissions or even if two arials are in use.
Art

Antenna Axial Ratio RHCP LHCP
 

art wrote:
On 14 Feb, 09:55, "David G. Nagel" wrote:
art wrote:
On 13 Feb, 22:18, "Jerry Martes" wrote:
"Bobby" wrote in message
ups.com...
All,
How do you determine the axial ratio from a RHCP wave to a LHCP wave
from an antenna? In essence, I need an axial ratio transformation from
RHCP to LHCP.
Any ideas on the equation or where I can find it will be helpful.
Thanks.
Bobby.
Hi Bobby
If you are working with an antenna that radiates RHCP it is totally
insensitive to LHCP.
If you have an antenna that radiates "RHCP" (or LHCP) the axial ratio is
the ratio of the Minor axis to the Major axis of the E field. So, it
varies from zero to one as the radiated field varies from Linear to
Circular.
Jerry
You mentioned insensetivity above, are there any other polarities
insensitive to others ? I note that weather antennas are now migrating
to
dual diversity antennas for horizontal and vertical, is it possible to
totally isolate those too.?
Art
Any cross polarization situation will exhibit insensitivity to others.
For instance take a vertical antenna and a horizontal antenna at a
distance. There is a signifant reduction in signal strength.
Or take a dipole oriented NS and a dipole oriented EW and you will see a
loss of signal also.

Dave WD9BDZ- Hide quoted text -

- Show quoted text -

David, could you add to your posting some of it doesn't seem to jive.
Art



Art;

OnPage 23.35 of the ARRL 2006 Handbook is a Graph showing the relative
loss between two antenna's for various angles from 0 degree to 90 degree
misalignment. For 0 degree misalignment there is no loss, at 50 degrees
there is a 3.84 dB loss and at 80 degrees there is a loss of 15.2 dB. 90
degree misalignment shows an infinate loss. This is for linear
antenna's. Circular Polarized antennas of opposite turns show an
infinate loss between two antenna's.
If I can help further please feel free to contact me direct:


Dave WD9BDZ

Antenna Axial Ratio RHCP LHCP
 

art wrote:
On 14 Feb, 11:01, "art" wrote:
On 14 Feb, 09:55, "David G. Nagel" wrote:





art wrote:
On 13 Feb, 22:18, "Jerry Martes" wrote:
"Bobby" wrote in message
ups.com...
All,
How do you determine the axial ratio from a RHCP wave to a LHCP wave
from an antenna? In essence, I need an axial ratio transformation from
RHCP to LHCP.
Any ideas on the equation or where I can find it will be helpful.
Thanks.
Bobby.
Hi Bobby
If you are working with an antenna that radiates RHCP it is totally
insensitive to LHCP.
If you have an antenna that radiates "RHCP" (or LHCP) the axial ratio is
the ratio of the Minor axis to the Major axis of the E field. So, it
varies from zero to one as the radiated field varies from Linear to
Circular.
Jerry
You mentioned insensetivity above, are there any other polarities
insensitive to others ? I note that weather antennas are now migrating
to
dual diversity antennas for horizontal and vertical, is it possible to
totally isolate those too.?
Art
Any cross polarization situation will exhibit insensitivity to others.
For instance take a vertical antenna and a horizontal antenna at a
distance. There is a signifant reduction in signal strength.
Or take a dipole oriented NS and a dipole oriented EW and you will see a
loss of signal also.
Dave WD9BDZ- Hide quoted text -
- Show quoted text -
David, could you add to your posting some of it doesn't seem to jive.
Art- Hide quoted text -

- Show quoted text -

David , maybe it was I that was not so clear.
My arials are based around a cluster of elements that are at various
placement with respect to each other tho all are resonant as is the
cluster as a whole. So when it is used for diversity operation because
more than one element is resonant choices can be made as to where to
feed to advantage
as quick as possible with a change over such that the reflection is
meaningful with respect to time. I don't believe that the weather
people radiate both at the same time as the search is for purity with
respect to polarity. In fact all the arials ive seen cannot possibly
be pure since they all seem to have elements in the vertical position
which cannot lead to purity in any form. I saw one in a antenna book
( shelnikov)where the elements were in helical form one behind the
other at a 90 degree offset but I have no further knoweledge of that
one. Somebody mentioned that some radios are now made with two ports
such that the receive portion automatically switches to the loudest
signal to overcome fading so I may well be incorrect about
simultaneous transmissions or even if two arials are in use.
Art

Art;

I responded to your other email but what you are saying here is that you
are using multiple antenna's which are selected automatically to sense
the strongest signal reguardless of the orientation of the received
signal. i.e. if the signal is at 45 degrees the antenna that is fixed to
a 45 degree angle will be the strongest signal. If I have it correct it
makes perfect sense but is not cross or circular polarization just
rotated wave front.

Dave WD9BDZ

Antenna Axial Ratio RHCP LHCP
 

"David G. Nagel" wrote in message
...

OnPage 23.35 of the ARRL 2006 Handbook is a Graph showing the relative
loss between two antenna's for various angles from 0 degree to 90 degree
misalignment. For 0 degree misalignment there is no loss, at 50 degrees
there is a 3.84 dB loss and at 80 degrees there is a loss of 15.2 dB. 90
degree misalignment shows an infinate loss. This is for linear
antenna's.

Yes. I wasted *hours* at Field Day a few years ago trying to make FM
contacts on 440 with my beam oriented parallel to the horizon. (I play with
TV DX and I brain-cramped with my 440 beam.)

When somebody pointed out my error, I wanted to crawl in a hole. This
monumental screwup came despite the fact that I had been making 2m contacts
with a correctly-oriented beam. Go figure. But it proved the heck out of
the theory!!!!

Antenna Axial Ratio RHCP LHCP
 

On 14 Feb, 18:46, "David G. Nagel" wrote:
art wrote:
On 14 Feb, 09:55, "David G. Nagel" wrote:
art wrote:
On 13 Feb, 22:18, "Jerry Martes" wrote:
"Bobby" wrote in message
egroups.com...
All,
How do you determine the axial ratio from a RHCP wave to a LHCP wave
from an antenna? In essence, I need an axial ratio transformation from
RHCP to LHCP.
Any ideas on the equation or where I can find it will be helpful.
Thanks.
Bobby.
Hi Bobby
If you are working with an antenna that radiates RHCP it is totally
insensitive to LHCP.
If you have an antenna that radiates "RHCP" (or LHCP) the axial ratio is
the ratio of the Minor axis to the Major axis of the E field. So, it
varies from zero to one as the radiated field varies from Linear to
Circular.
Jerry
You mentioned insensetivity above, are there any other polarities
insensitive to others ? I note that weather antennas are now migrating
to
dual diversity antennas for horizontal and vertical, is it possible to
totally isolate those too.?
Art
Any cross polarization situation will exhibit insensitivity to others.
For instance take a vertical antenna and a horizontal antenna at a
distance. There is a signifant reduction in signal strength.
Or take a dipole oriented NS and a dipole oriented EW and you will see a
loss of signal also.

Dave WD9BDZ- Hide quoted text -

- Show quoted text -

David, could you add to your posting some of it doesn't seem to jive.
Art

Art;

OnPage 23.35 of the ARRL 2006 Handbook is a Graph showing the relative
loss between two antenna's for various angles from 0 degree to 90 degree
misalignment. For 0 degree misalignment there is no loss, at 50 degrees
there is a 3.84 dB loss and at 80 degrees there is a loss of 15.2 dB. 90
degree misalignment shows an infinate loss. This is for linear
antenna's. Circular Polarized antennas of opposite turns show an
infinate loss between two antenna's.
If I can help further please feel free to contact me direct:


Dave WD9BDZ- Hide quoted text -

- Show quoted text -

David I am not privy to a copy of what you are talking about but we
may be talking at cross purposes. My point is that a element at right
angles or parallel to the earths surface cannot present a pure
polarised field.
When looking at a radiating beam you have two vectors, one at right
angles to the other, therefore I fail to see how radiation would
appear at right angles to the earths surface. True the right angled
vector is reduced when it is broken up into two vectors when it is
seen as curl but the horizontal vector cannot be removed or cancelled
unless the element is tilted somewhat.
Anybody can prove this to themselves by the use of the plethora of
computor programs Admittedly the tilt required is small but it is
there none the less.
Art

Antenna Axial Ratio RHCP LHCP
 

Sal M. Onella wrote:
"David G. Nagel" wrote in message
...

OnPage 23.35 of the ARRL 2006 Handbook is a Graph showing the relative
loss between two antenna's for various angles from 0 degree to 90 degree
misalignment. For 0 degree misalignment there is no loss, at 50 degrees
there is a 3.84 dB loss and at 80 degrees there is a loss of 15.2 dB. 90
degree misalignment shows an infinate loss. This is for linear
antenna's.

Yes. I wasted *hours* at Field Day a few years ago trying to make FM
contacts on 440 with my beam oriented parallel to the horizon. (I play with
TV DX and I brain-cramped with my 440 beam.)

When somebody pointed out my error, I wanted to crawl in a hole. This
monumental screwup came despite the fact that I had been making 2m contacts
with a correctly-oriented beam. Go figure. But it proved the heck out of
the theory!!!!




It's called a brain fart...

It's also why antenna science is an ART.


Dave WD9BDZ

Antenna Axial Ratio RHCP LHCP
 

art wrote:
On 14 Feb, 18:46, "David G. Nagel" wrote:
art wrote:
On 14 Feb, 09:55, "David G. Nagel" wrote:
art wrote:
On 13 Feb, 22:18, "Jerry Martes" wrote:
"Bobby" wrote in message
ups.com...
All,
How do you determine the axial ratio from a RHCP wave to a LHCP wave
from an antenna? In essence, I need an axial ratio transformation from
RHCP to LHCP.
Any ideas on the equation or where I can find it will be helpful.
Thanks.
Bobby.
Hi Bobby
If you are working with an antenna that radiates RHCP it is totally
insensitive to LHCP.
If you have an antenna that radiates "RHCP" (or LHCP) the axial ratio is
the ratio of the Minor axis to the Major axis of the E field. So, it
varies from zero to one as the radiated field varies from Linear to
Circular.
Jerry
You mentioned insensetivity above, are there any other polarities
insensitive to others ? I note that weather antennas are now migrating
to
dual diversity antennas for horizontal and vertical, is it possible to
totally isolate those too.?
Art
Any cross polarization situation will exhibit insensitivity to others.
For instance take a vertical antenna and a horizontal antenna at a
distance. There is a signifant reduction in signal strength.
Or take a dipole oriented NS and a dipole oriented EW and you will see a
loss of signal also.
Dave WD9BDZ- Hide quoted text -
- Show quoted text -
David, could you add to your posting some of it doesn't seem to jive.
Art
Art;

OnPage 23.35 of the ARRL 2006 Handbook is a Graph showing the relative
loss between two antenna's for various angles from 0 degree to 90 degree
misalignment. For 0 degree misalignment there is no loss, at 50 degrees
there is a 3.84 dB loss and at 80 degrees there is a loss of 15.2 dB. 90
degree misalignment shows an infinate loss. This is for linear
antenna's. Circular Polarized antennas of opposite turns show an
infinate loss between two antenna's.
If I can help further please feel free to contact me direct:


Dave WD9BDZ- Hide quoted text -

- Show quoted text -

David I am not privy to a copy of what you are talking about but we
may be talking at cross purposes. My point is that a element at right
angles or parallel to the earths surface cannot present a pure
polarised field.
When looking at a radiating beam you have two vectors, one at right
angles to the other, therefore I fail to see how radiation would
appear at right angles to the earths surface. True the right angled
vector is reduced when it is broken up into two vectors when it is
seen as curl but the horizontal vector cannot be removed or cancelled
unless the element is tilted somewhat.
Anybody can prove this to themselves by the use of the plethora of
computor programs Admittedly the tilt required is small but it is
there none the less.
Art


Art;

Your right horizontal is horizontal and vertical is vertical and never
the twain shall meet.

Dave

Antenna Axial Ratio RHCP LHCP
 

On 15 Feb, 07:48, "David G. Nagel" wrote:
art wrote:
On 14 Feb, 18:46, "David G. Nagel" wrote:
art wrote:
On 14 Feb, 09:55, "David G. Nagel" wrote:
art wrote:
On 13 Feb, 22:18, "Jerry Martes" wrote:
"Bobby" wrote in message
glegroups.com...
All,
How do you determine the axial ratio from a RHCP wave to a LHCP wave
from an antenna? In essence, I need an axial ratio transformation from
RHCP to LHCP.
Any ideas on the equation or where I can find it will be helpful.
Thanks.
Bobby.
Hi Bobby
If you are working with an antenna that radiates RHCP it is totally
insensitive to LHCP.
If you have an antenna that radiates "RHCP" (or LHCP) the axial ratio is
the ratio of the Minor axis to the Major axis of the E field. So, it
varies from zero to one as the radiated field varies from Linear to
Circular.
Jerry
You mentioned insensetivity above, are there any other polarities
insensitive to others ? I note that weather antennas are now migrating
to
dual diversity antennas for horizontal and vertical, is it possible to
totally isolate those too.?
Art
Any cross polarization situation will exhibit insensitivity to others.
For instance take a vertical antenna and a horizontal antenna at a
distance. There is a signifant reduction in signal strength.
Or take a dipole oriented NS and a dipole oriented EW and you will see a
loss of signal also.
Dave WD9BDZ- Hide quoted text -
- Show quoted text -
David, could you add to your posting some of it doesn't seem to jive.
Art
Art;

OnPage 23.35 of the ARRL 2006 Handbook is a Graph showing the relative
loss between two antenna's for various angles from 0 degree to 90 degree
misalignment. For 0 degree misalignment there is no loss, at 50 degrees
there is a 3.84 dB loss and at 80 degrees there is a loss of 15.2 dB. 90
degree misalignment shows an infinate loss. This is for linear
antenna's. Circular Polarized antennas of opposite turns show an
infinate loss between two antenna's.
If I can help further please feel free to contact me direct:


Dave WD9BDZ- Hide quoted text -

- Show quoted text -

David I am not privy to a copy of what you are talking about but we
may be talking at cross purposes. My point is that a element at right
angles or parallel to the earths surface cannot present a pure
polarised field.
When looking at a radiating beam you have two vectors, one at right
angles to the other, therefore I fail to see how radiation would
appear at right angles to the earths surface. True the right angled
vector is reduced when it is broken up into two vectors when it is
seen as curl but the horizontal vector cannot be removed or cancelled
unless the element is tilted somewhat.
Anybody can prove this to themselves by the use of the plethora of
computor programs Admittedly the tilt required is small but it is
there none the less.
Art

Art;

Your right horizontal is horizontal and vertical is vertical and never
the twain shall meet.

Dave- Hide quoted text -

- Show quoted text -

But David they must meet otherwise radiation cannot occur !

Antenna Axial Ratio RHCP LHCP
 

Bobby wrote:
All,

How do you determine the axial ratio from a RHCP wave to a LHCP wave
from an antenna? In essence, I need an axial ratio transformation from
RHCP to LHCP.

Any ideas on the equation or where I can find it will be helpful.

That's an easy one.

The axial ratio of a purely RHCP wave is 1. The axial ratio of a purely
LHCP wave is 1. The transformation would be 1 = 1.

Roy Lewallen, W7EL