Microwave frequency discriminating devices based on composite right-/left-handed transmission-line unit-cell

This paper reviews and presents design approaches for microwave filter and multiplexers based on resonant-type composite right/left-handed metamaterial. The proposed filter design offers better transmission performances in terms of insertion losses and out-of-band rejection. In addition, it enables substantial tuning to be achieved in the order of over 30 % at the unit-cell's resonant frequency. The passband channels inside the new diplexer/triplexer topology have high isolation between them which is critical in order to prevent undesired interaction which would otherwise adversely affect their passband response.