Excellent wideband and low corss polarization @ phi=45 antenna 1

[John.Jin]

Hello,

I hope all of you have started a good day. It is my first post on this site and I hope to get good information from your experience.

I need to rotate 45 degrees a linear polarized antenna at the focal point of a symmetrical reflector antenna to receive vertical and horizontal signals with 3dB loss.

So the dominant fields are fields @ phi=45 and in the cross-polarization pattern @ phi=45, I need to have an antenna with a low cross-polarization pattern @ phi=45.

I used a double-rigged horn antenna (gain > 7 dBi @ F=3Ghz and gain<14 dBi @ F=12Ghz) but the cross-polarization @ phi=45 is unacceptable.

I changed the double ridged horn antenna to a planar log periodic antenna whose cross-polarization @ phi=45 is excellent(the gain was less than -10dbi) but regarding the different dipole antennae at different positions, the phase center changes for each frequency a lot, and regarding the limited gain(less than 9dBi @ f=12Ghz), the reflector antenna pattern shows many sidelobes.

LPDA pattern:

I would be thankful if you could introduce me to an antenna that has these specifications:

1)WideBand: 3-12Ghz
2)Low Cross-polarization @ phi=45
3)High gain: gain more than 7dbi @ 3Ghz

Many thanks.