摘要 |
An amplifier/duplexer for an antenna channel of a radar apparatus, comprises a first hybrid junction having two input/output ports for connection into the antenna channel, and two further ports each connected to a parallel combination comprising an amplifier and switching means switchable between a transmit condition in which it presents an open circuit and a receive condition in which it presents a short circuit so that a signal received in the antenna channel is applied to one of the input/output ports and reflected to the other input/output port each amplifier having an input connected to a respective output port of a further hybrid junction, an input port of the further hybrid junction being configured to receive a signal for transmission so that when the switching means is in the transmit condition the transmission signal is amplified by the amplifiers and delivered through the first hybrid junction to the antenna channel. |