Inverted Diamond-shaped Notched Substrate and Patch for High-frequency Interference on Ultra-wideband Antenna

Notches loaded on a patch antenna can affect significantly on ‎ the antenna impedance matching. Therefore, notching technique is an efficient way to reduce ‎ the electromagnetic interference with unwanted bands. In this paper, a ‎ novel inverted diamond ‏-‏ shaped closed-end slot on a substrate and ‎ vertex-fed printed hexagonal patch ultra ‏-‏ wideband antenna is proposed for high-frequency band rejection. This antenna is fed using ‎ coplanar waveguide, and it is optimised by veering several patch ‎ parameters which further improved the inter bandwidth at both the ‎ lower and upper bands. However, the centre-notched band is shifted ‎ from 6 GHz to 7.5 GHz by cutting the inverted diamond shape in a ‎ special process. The developed ultra-wideband antenna is verified by ‎ comparing the simulation results with the measurement results. The ‎ measured results with a fractional bandwidth of 133% have a good ‎ agreement with the simulation results 146%. Moreover, the measured radiation showed omnidirectional patterns ‎ .