A compact dielectric resonator antenna (DRA) suitable for wideband applications is presented in this paper. The proposed antenna is mainly composed by a notched cylindrical dielectric resonator (DR) coated with a metal surface on the top and a finite ground plane where the presented DR is placed. This antenna is very simple in structure and has a very low overall height of0.14λminat its lowest operation frequency. A comprehensive parametric study is carried out based on Ansoft HFSS to optimize the bandwidth. The proposed antenna has been successfully simulated, optimized, fabricated, and measured. The measurement results demonstrate that the proposed design produces an impedance bandwidth of more than 75%, ranging from 2.9 GHz to 6.7 GHz for the reflection coefficient less than −10 dB. In particular, consistent broadside radiation patterns, stable gain, and high radiation efficiency are also obtained within the operation frequency band.

In this study, a compact ultra-wideband (UWB) antenna with quintuple band-notched and wide-band rejection characteristics is studied. The proposed antenna mainly consists of a rectangular radiating patch, a microstrip feeding line, and a modified rectangular ground plane. The quintuple band-notched functions with narrow stop bands are achieved at WiMAX (3.3–3.7 GHz), WLAN (5.15–5.35 GHz and 5.725–5.825 GHz), C-band IEEE INSAT/super-extended (6.7–7.1 GHz) by using three modified inverted U-shaped slots and two symmetrical rectangular slots on the radiating path. Each stop band formed in the UWB antenna can be adjusted independently, and deep reflection zeros are formed between the adjacent stop bands. The formation of reflection zeros improves the band-edge selectivity of the stop band, and the notch characteristics are more prominent. To further study the wide stop band (C-band and X-band) with good selectivity characteristics, a pair of L-shaped open slot is added to the edges of two rectangular slots. Additionally, a pair of modified Rho-shaped resonators is located near the feeding line to realize band-notched characteristic at ITU service bands (8.025–8.4 GHz), thus a quintuple band-notched UWB antenna is achieved. The shape factor (ratio of the −3 dB bandwidth to the −10 dB bandwidth) of the wide stop band is 0.56, which indicates that the antenna has excellent band-edge selectivity. To verify the performance of the proposed design, both the time-domain and the frequency-domain characteristics of the antenna have been studied and analyzed. The simulated and measured results verify the design as a good candidate for various portable UWB applications.

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A novel design method of ultra wide filter based on the composite right/left-handed transmission line (CRLH-TL) theory is presented in paper. The composite right/left-handed TL with the high-pass characters of left-handed transmission line (LH-TL) and the low-pass characters of right-handed transmission line (RH-TL) are used to construct the ultra wideband (UWB) bandpass filter. Defected ground structure (DGS) and microstrip interdigital capacitors are introduced to satisfy the necessity of the UWB filter. The many cells composite right/left-handed UWB filters are fabricated and measured. Agreement between simulated and measured responses of these filters is demonstrated