This paper presents our recently proposed multi-state diplexers (MSDs) implemented on different structures. The proposed MSDs have inherent property of multiple frequency channels, two of which can be used for duplexing mechanism by exciting one port as the input in each state. The MSDs have an attractive application in frequency hopping communication systems with miniaturization in their overall sizes. Then, three approaches to design the MSDs using different structures (planar triple-mode resonator, triple-mode cavity resonator and uniform/stepped impedance stub-loaded resonators) are presented. All the MSDs are finally fabricated and measured, the measurement are in good agreement with the simulation.