Left-handed L-band notch bandstop filter with significantly reduced size

An innovative compact microstrip line left-handed (LH) L-band notch bandstop filter is presented, validated by full-wave simulations and demonstrated by experiments, showing that the size of the filter can be significantly reduced by employing the LH transmission line (TL) metamaterials. The proposed notch bandstop filter was constructed using coupled line coupler loaded with 90deg LH TL. The size of the fabricated LH filter is 4.4 times smaller than that of the filter loaded with -270deg conventional TL and nearly two times smaller than that of the filter loaded with -270deg meandered TL. The filter has a centre frequency of 1.164 GHz and a fractional bandwidth of 0.51%. The loaded quality factor of the filter is 197, indicating 64 and 97% increases in comparison with the conventional and meandered TL filters, respectively