Design of Diplexer for LTE-28/26 band using D-CRLH transmission line Metamaterials

Diplexer is a three port device that combines or split signals for different frequency, the three ports is combined with a T-junction. Diplexers are mainly employed to route signals of two different receivers depending on frequencies. The D-CRLH transmission line has the dual property such that It has a series parallel LC tank (instead of series) and a shunt series LC tank (instead of parallel). The D-CRLH transmission line is used to realize the diplexer, as it has the advantage of small size for high frequency band compared to conventional diplexers. The diplexer is designed to reach the detailed description with respect to size, return loss and insertion loss at input and output ports. The paper presents the design of diplexer using Dual Composite Right Left Handed Metamaterials (D-CRLH MTM). The design contains two band stop (notch) filter with different stop band. Using Advanced Digital Simulation (ADS) tool the design for the frequency to split is LTE 725/831 MHz is simulated. Based on the simulation it is observed that the insertion loss for LTE band (28) is -106.244 dB and for LTE band (26) is -129.340dB. Thus the insertion loss for both frequencies is deeper that ensures the signal at specific range is attenuated using D-CRLH transmission line.