An amplifier system includes a power divider for dividing an input RF
signal into M RF signals of equal power and phase. The system has M low
power selectable phase shifters each for phase shifting one of the M RF
signals. M high power amplifiers are coupled to respective ones of the
phase shifters. The system includes an M.times.N power distribution
network having M input ports and N output ports, such as a Butler matrix.
The M high power amplifiers are connected to a respective one of the M
input ports of the distribution network. The phase of the M phase
shifters may be adjusted to obtain a maximum output at the desired output
with all the other outputs nulled.