It is desired to design a uniform ordinary end-fire array of 6 elements with a maximum toward theta o = 0° and 0, = 180°, simultaneously. Determine the (a) smallest separation between the elements (in 1). (b) excitation progressive phase shift (in degrees) that should be used (d) relative value (in dB) of the magnitude of the array factor toward broadside (0, = 90°)compared to that toward the maximum (theta, = 0° or 180°). (c) approximate directivity of the array (dimensionless and in dB)