Composite Right/Left Handed Metamaterial Structures for RF Narrow Bandpass Filter Design

In this paper we have proposed Metamaterial based Composite Right-Left Handed transmission line new structure with microstrip gap capacitors and open stub inductors. By using this structure and also to check the possibility of performance, we have designed narrow bandwidth RF bandpass filter in shielded suspended substrate for EGSM base station applications (Tx band, 925MHz - 960MHz). To validate the proposed structured design and analysis, the layout board of bandpass filter was fabricated and measured. It is shown that the simulated and measured performances are good in agreement. For three unit cells within a narrow bandwidth of 35 MHz, the layout board of bandpass filter has achieved an insertion loss of nearly -0.7 dB and a stopband of -10 dB approximately.