A goblet-shaped quad band-notched UWB antenna and its MIMO configurations

Abstract

A goblet-shaped quad band-notched antenna is proposed as a prototype antenna. With three CSRR slots and two symmetrical C-like metal stubs, the antenna produced four notched bands to suppress 3.5 GHz WiMAX, 5.3 GHz lower band of WLAN, 5.8 GHz upper band of WLAN and 8.3 GHz X-band. To increase channel capacity and data rate, a two-port UWB-MIMO antenna-1 with quad notched-bands is introduced by placing two identical prototype antenna perpendicularly. The UWB-MIMO antenna-1 easily achieves high isolation of more than 25 dB, but it has big volume of 30 × 60 × 0.8 mm3. To keep miniaturization in size, a two-port UWB-MIMO antenna-2 is constructed by arranging two identical prototype antenna in parallel. With a slot in the common ground and an I-type metal parasitic stub, better than 15 dB port isolation is realized. The simulated and measured data indicate that the UWB-MIMO antenna-2 can reject the above four bands in working band of 3–11 GHz. Meanwhile, other characteristics of high port isolation, good radiation pattern and stable gain are observed. Having compact structure and favorable characteristics, the UWB-MIMO antenna-2 not only realized four notch bands, but also effectively improved the spectrum utilization, which is the highlight of the work.