Mutual Coupling Reduction Between Two PIFA Using Uni-Planar Fractal Based EBG for MIMO Application

Abstract

Fractal Structures based on Electromagnetic bandgap (EBG) can contribute to the mutual coupling reduction between microstrip antennas due to its capability of suppressing surface waves propagation in a given frequency range. In this paper, a new arrangement of one layer Uni-Planar Fractal based on EBG (UPF-EBG) structure is analysed using the commercial finite element full wave solver High-Frequency Structure Simulation (HFSS version 17.0). The structure without any shorting pins or vias is based on a well-known fractal structure called Sierpinski carpet, within which two iterations have been applied as planner EBG between two PIFA for increase isolation issue. The total dimensions of the PIFA antenna are 40 mm × 68 mm × 1.6 mm and operate at 2.65 GHz approximately which is defined for wireless Long Term Evolution (LTE) MIMO application. Here a compact periodic lattice (2 × 3 EBG structures are joint to improve the mutual coupling) inserted between E-plane coupled PIFA array, and precise performance study is implemented to investigate the mutual coupling. As a result, significantly more than 30 dB mutual coupling reduction is noticed from the simulations.