Design and simulation of microwave diplexer based on D-CRLH metamaterials

In this paper, we propose a design of diplexer based on Dual Composite Right-Left Handed metamaterial (D-CRLH-MTM). The diplexer is practically a 3 port structure having one input and two output ports, the 3-port is constituted with a T-junction. The structure consists of two notch filter having different stop band with a common input port (diplexer input) and output ports of two filters acts as diplexer output. The notch filter is realized with D-CRLH TL and shunted to the main transmission line. In this work the diplexer is required to meet some stringent specifications regarding size, insertion loss and return loss at input and output ports. The frequency response is obtained and the performance of the diplexer is investigated. The target frequency to separate is GSM 900/1800 MHz.