Co-designed defected ground structure filter with UWB slot antenna

Abstract

In this study, one kind of novel co-designed defected ground structure (DGS) filter with slot antenna is proposed to realize bandpass reflection coefficient and gain performance. This antenna consists of two parts: 1) a 50 Ω feeding line and 2) a modified stepped slot with additional narrow slot and defected ground structure. The extra narrow slot, which can effectively prolong the current path of low frequency and generate reflection zero, is introduced to improve the lower band-edge selectivity. DGS is used to improve the upper band-edge selectivity, which can produce transmission zeros in certain frequencies and provides excellent stopband characteristics. In addition, the modified stepped slot with DGS can produce additional resonance frequency, which is helpful to improve the in-band impedance characteristics and radiation efficiency of the antenna. Measured results show that not only the band-edge selectivity of the antenna is improved, but also the in-band impedance matching and radiation efficiency are improved. The experimental results show that the proposed design could be a good candidate for UWB applications.