DUPLEX RELAY AMPLIFIER

PURPOSE:To eliminate the loss of input output hybrids and to reduce the circuit scale and the cost by constituting a duplex relay amplifier of 4 directional filters which separate outgoing and incoming signals and one amplifier. CONSTITUTION:The amplifier is provided with a 1st directional filter 3 connected to an up direction transmission line and separating an input signal into a high frequency band down signal, and into a low frequency up signal with a 2nd directional filter 4 connected to a down direction transmission line and separating an input signal into a down signal and into an up signal. Also, a 3rd directional filter 6 is provided to receive a down signal outputted by the 1st directional filter 3 and an up signal outputted by the 2nd directional filter 6 respectively and to output a mixed signal. Moreover, the amplifier is provided with an amplifier 7 amplifying the mixed signal and a 4th directional filter 5 separating the output signal of the amplifier 7 into down signal and an up signal and supplying them to the 2nd directional filter 4 and the 1st directional filter 3. Thus, the decrease in the output level by using the hybrid is prevented.