A DBS antenna is characterized by the simultaneous availability of three beams: 1. A sum beam through which all data is transferred. 2. A monopulse difference beam used for target direction finding. 3. A control beam. Its function is to guarantee that all transactions occur in the main beam. Whereas the desirable azimuth characteristics arise from the basic required functions and from the necessity to minimize the effects of the RF (target) environment, the desirable elevation features are such as to reduce the effects of the physical environment. Implementation options are very sensitive to the type (if any) of primary radar with which it is to be collocated.