Circuit which connects decoupled transmitters to antenna - uses two directional couplers and two phase shifters cross-coupled between third and fourth ports

摘要

The circuit consists of two identical directional couplers (RK1,RK2) each of whose first ports is connected to a transmitter (S1,S2). The two transmitters have different frequencies. The second ports are connected to the shared antenna (A). The third ports of the two couplers are connected together via a second phase shifter (P2). The fourth ports of the couplers are connected together by a first phase shifter (P1). The phase shifters may be cross-coupled from third to fourth ports or may be combined into a 4-pole phase shifter. The phase shifters and input and output impedances of the couplers are chosen to fulfil specified conditions.