Dual Pin Fed Patch, circular Question

[RFCD]

Hi,

I'm a little bit confused about a dual pin fed patch antenna.
The antenna is feeded by 2 pins, one pin is 0° and the other one is -90°
But I`m not sure what is LHCP and what is RHCP.

------------------------
I..............................I
I..............................I
I..............................I
I.......................X.....I
I..............................I
I..............................I
I..............................I
I...............Y.............I
-----------------------
View from the back of the antenna

Y = 0°
X = -90°

Y = -90°
X = 0°

What do you mean?

Kind regards
RFCD

 

[vfone]

This depends by the feed combiner output.

 

[RFCD]

I think the combiner output doesn't metter here because I want to understand what happens if I put two signals to the Antenna with 0° and 90°.

For my understanding:

LHCP
Y = 0°
X = -90°

RHCP
Y = -90°
X = 0°

But im not realy sure :???:

 

[vfone]

So, how do you want to feed the patch without a 90-deg combiner?

 

[RFCD]

I don`t have a problem with understanding -90° combiner....
I could use a printetd circuit or a quadartur hybrid chip or build a quarter wave line...

So back to my question, I wrote that this antenna will be feeded with two signals so I still have 0° and 90°.
But on which pin which signal for LHCP / RHCP?

 

[vfone]

When the phase difference between X and Y is +90 deg is RHCP, and when the phase difference between X and Y is -90 deg than is LHCP.