A two-beam slotted leaky waveguide array for mobile reception of dual-polar
ization direct broadcast from satellite (DBS) is realized in a single-layer
structure. Two feed waveguides attached at both ends of cross-slotted radi
ating waveguides excite the leaky waves propagating in opposite directions.
Each of them radiates either of two circularly polarized waves in symmetri
cal beam directions. Balanced design of two beams for each polarization imp
oses symmetry in the array design of slots. The slot coupling distribution
is optimized for the maximum gain under this symmetry condition, A model an
tenna in about a 300-mm square is fabricated for experiments in the 12-GHz
band. Antenna efficiency of 71% and 64% is obtained for each beam in differ
ent polarizations.