A Note on Super-Gain Antenna Arrays

Numerical calculations have been made for linear broadside super-gain arrays. Using arrays having an over-all length of a quarter wavelength as an example, it is shown that as the required directive gain is increased, tremendous currents are required to produce only a small radiated field. For a 9-element array which produces a power gain of 8.5, the currents must be adjusted to their correct value to an accuracy of better than 1 part in 1011. The efficiency is less than 10-14 per cent.