Calculations showing the reduction in the frequency dependence of a two-element array antenna fed by microwave transistors

The variation with frequency of the radiated field in a given direction from a transistor-fed array is shown to be markedly reduced in comparison to the corresponding variation in a passive array. The
Q
factors of both types of arrays are computed for endfire and broadside excitations. It is shown that a considerable reduction in the values of
Q
is obtained when the array is fed via transistors. There is seen to be a good correlation between values of
Q
and the bandwidth of the normalized radiated field in a given direction.