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.