Defected I-Shaped Patch with Fountain-Pen Nib Slot and Partial-Ground Four-Port MIMO Antenna for Ku-Band Applications

The proposed design features a four-port (Multiple Input Multiple Output<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">KU-Band</inf>) MIMO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">KU-Band</inf> antenna utilizing slot and stub techniques proposed for applications in the KU-Band. Employing Rogers RT Duroid substrate with a thickness of 0.787mm and dimensions of 20×18 mm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup>, characterized by a loss tangent of 2.2, the antenna targets satellite and defence applications within the KU-Band. Overcoming the challenge of maintaining isolation between adjacent elements without the use of any decoupling structure, this design methodology proves effective. The design incorporates a rectangular-shaped radiating patch with a nib-shaped slot and a circular slot on the ground, serving as a defective ground structure to achieve resonance in the KU-Band. Overall, the antenna demonstrates remarkable characteristics in terms of gain, as well as diversity parameters such as Envelope Correlation Coefficient (ECC<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">KU-Band</inf>), Diversity Gain (DG<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">KU-Band</inf>), Total Active Reflection Coefficient (TARC<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">KU-Band</inf>), and Channel Capacity Loss (CCL<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">KU-Band</inf>), attributed to the utilization of slot and stub techniques in both the ground and radiating surfaces. At 15.0 GHz, the designed antenna achieves a gain of 4.5 dBi, with omnidirectional radiation patterns observed in both planes. The proposed structure exhibits excellent performance tailored for satellite and defence applications within the KU-Band.