A high power X-band Butler matrix

Feasibility studies of waveguide high power Butler matrices of arbitrary complexity have been completed. Component imperfections were simulated using a specially developed computer analysis program. This is capable of analyzing Butler matrices of up to 64 elements, far in excess of the capacity of general purpose programs. Computer results indicated that good performance could be expected over a 10 percent frequency band using practical hybrids and phase shifters. This was confirmed from results taken on a prototype 8-element Butler matrix constructed in WR112. The maximum phase error between any pair of input and output ports is 6 deg, with an RMS error of less than 3 deg. The coupling to the output ports showed a variation of 0.45 dB, and the dissipation loss of the unplated aluminum unit is 0.4 dB.