A power amplifier structure having: a power divider for dividing power in a signal fed to an input port between a pair of output ports. Each one of a pair of amplifiers has: an input coupled to a corresponding one of the pair of power divider output ports; and an output. A power combiner is provided. Signals at the power divider output ports are fed to the inputs of the pair of amplifiers in a forward direction and then pass through the amplifiers in the forward direction towards the outputs of the pair of amplifiers. Connectors direct the signals at the amplifier outputs to the power combiners, the signal then passing through the power combiner to an output port in a direction opposite to the forward direction.