An exponentially tapered slot antenna assembly includes a plurality of antenna panels arranged together in a general box-like configuration. At each corner of the box-like configuration, a capacitive load panel is in operative electrical communication with orthogonal pairs of antenna panels. Each antenna panel defines an inner and outer surface and has an electromagnetic interference shielding material positioned thereon. The shielding material positioned may be positioned near a first or upper edge of each antenna panel of the assembly. It has been empirically determined that this configuration enables an operational bandwidth that is greater than 5:1 and a voltage standing wave ratio that is less than 3:1 over the 5:1 bandwidth.