To provide a patch antenna assembly having many more antennas having respective operating frequency bands with improved frequency band isolation.

The assembly is configured by stacking a plurality of patch antennas 103, 105, 107, and 109. Each antenna has a radiating patch (103a, 105a, 107a, and 109a), and a first cable 111 has a plurality of coaxial conductors 111a, 111c separated by a dielectric. The first coaxial conductor carries a feed signal for the uppermost antenna 103 and is conductively coupled to a null point of the radiating conductive patch 103a of the uppermost antenna 103 and passes through apertures 123, 125, 127 at the null points of the other antennas. Each of the successively lower antennas 105, 107, 109 is coupled to the other conductor 111c of the first cable, which conductors reference the other patches to ground. With this arrangement, high isolation is maintained between the frequency operating bands.