connected (Marchand) baluns and one single-section uniform
coupled-line quadrature hybrid. [6] The feed network provides
approximately equal amplitude power distribution and a
progressive 90 degree phase shift across its Ports 3, 4, 5, and 6,
which are each connected to a feed probe of the patch antenna.
SubMiniature version A (SMA) connectors are soldered to Port
1 and Port 2. Port 1 corresponds to left hand circular
polarization (LHCP) from the patch antenna, and Port 2
corresponds to right hand circular polarization (RHCP). Figure
2 shows the internal trace layout of the feed network and the
fabricated circuit board.