Electromagnetic Performance Comparison of an Offset and a Conventional Mma Antenna Design

Two potential MMA antenna designs are compared with respect to sensitivity, polarization purity, field-of-view and sidelobe level. Under conditions of very low atmospheric opacity and receiver noise temperature the offset reflector design has better sensitivity than the minimum blockage conventional design at about the 10% level. The offset design has poorer performance than the conventional design in the areas of polarization purity and field-of-view. If these problems with the offset design are cured using additional reflectors in the optics path then the sensitivity advantage of the offset design is lost.