The boresight sum gain and difference sensitivity of a Cassegrain reflector system fed by a four element array

The casaegrain reflector, when fed by a four element array, finds very common usage as an amplitude comparison monopulse system. The boresight sum gain and difference sensitivity essentially determine the range and pointing accuracy of the system. Although much is known about the cassegrain reflector [1] and extensive work has been done on an idealized parabolic reflector monopulse system as a function of feed size and excitation [2], little has been published on the cassegrain monopulse system.