Isolation Enhancement in a Microstrip Fed Compact Ultra-wideband Diversity Antenna by Exploring Koch Boundary Fractal and Extended Ground Stub

Abstract

This contribution, nominates and investigates a compact two element micro-strip fed 8-shaped self-affine fractal inspired Ultra-wideband (UWB) Multiple-Input-Multiple-Output (MIMO) antenna. The configuration exploits a 2nd order 8-shaped self-affine structure miniaturization of the overall size of each monopole element and provides wideband attributes to the antenna. The antenna exhibits an impedance bandwidth ranging from 2.6 GHz to 12 GHz, covering the entire UWB spectrum. The two element wideband MIMO antenna is realized within a compact layout of 32.3 mm×36.2 mm=1169.3 mm2. The isolation among the pair of planar monopoles with 2nd order Koch fractal boundary is found to be > −20 dB throughout the UWB spectrum even with a marginal inter-element spacing of 9.55 mm. The wideband isolation enhancement is also attained as a result of an extended ground stub with Koch fractal boundary. Moreover, the envelope correlation coefficient (ECC) of the UWB MIMO antenna is calculated to be < 0.01. The concurrence admits the diverse simulation results verify that the proposed arrangement can be a worthy competitor for handy UWB as well as UWB MIMO systems.