Microstrip triplexer and switchable triplexer using new impedance matching circuits

A triplexer with new impedance matching circuit (IMC) is presented in this article firstly, which exhibits compact size, low insertion loss, and wide passband. Then, the series‐parallel configuration p‐i‐n diode switches are introduced in the above IMC, and a new switchable impedance matching circuit is proposed to design a switchable triplexer. The designed switchable triplexer has eight available operation states, so that it realizes multiple functional blocks in a single module. The fabricated switchable triplexer also features compact size, wide passband, high isolation, and independently switchable operation states.