Microwave and millimetre-wave receivers with integral antenna

Ellipsoidal and hyperboloidal lens aperture functions for computation of fraunhofer diffraction patterns

“…5 , but modified for the ellipsoid, relates the differential quantities through Eq. (14) as Using once again the arguments leading to Eq. (4), but applied to Figure 5 tending angle 2PHMAXIMUM = 0.877 radians at the focal point.…”