Dual feed patch antenna with single connector
Found at:
https://d3i71xaburhd42.cloudfront.ne...-Figure3-1.png
you can use delay line or hybrid. Or you can create an array.
can i use probe feed with the network?
as in, use a 90 degree microstrip phase shifter beneath the substrate and connect it to the patch via a connecting/shorting pin?
I guess you can, as long as you make sure the phase difference doesn't change.
David Pozar, Microwave Engineering; discusses various feeding methods for patches to achieve circular polarization. Similar examples are cited in other antenna references. IEEE TAP will have numerous examples. The basic idea is to excite orthogonal modes and quadrature phase. This is easier with dual feeds but is can also be done with a single feed. With a square or nearly square patch the feed is often placed along the diagonal of the patch.
Regards,
Azulykit