In this paper, a miniaturized fully inkjet-printed flexible multiple-input-multiple-output (MIMO) antenna for ultrawideband (UWB) application is proposed, occupying a compact size of $22 imes 31 imes 0.125$ mm3.In Coffee Scoop the proposed antenna, two half-planar radiators are introduced to minimize the antenna size.Moreover, a modified T-shaped stub is employed on the ground plane to improve the impedance performance.
In addition, a slot is etched on this modified T-shaped ground stub to further enhance the isolation.By doing so, the proposed antenna can operate from 2.9 to more than 12 GHz with the mutual coupling less than −15 dB.Furthermore, to address the out-of-band characteristic drawback that existed in most of the previous UWB antenna, a parallel coupled band-pass filter with stepped impedance transformation and defected ground structure is incorporated in the feedline of the antenna to achieve sharp rejection at Stethoscopes - Binaural Stethoscopes the edges of the UWB band.
The measurements indicate that the proposed filter-antenna can cover from 3.43 to 10.1 GHz, with the envelope correlation coefficient below 0.3 and the channel capacity loss below 0.
4 bit/s/Hz, which ensures its good MIMO performance.