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In this communication, a new compact ultra‐wideband (UWB) multiple‐input multiple‐output (MIMO) antenna with band notch characteristics is presented for wireless application. It comprises of two unique monopole antenna elements sharing a similar ground plane. To reduce the coupling between antenna elements, a modified T‐shaped stub equipped with Minkowski fractal shape elements are introduced on the ground plane which in turn establish a good isolation between radiating elements. A band notch is achieved at 5.45 GHz by adding two additional rectangular stubs at 45° where symmetric slots have been etched. The efficiency and gain of the antenna drops significantly at the centre of the notch band which indicates good interference suppression. Results show that the designed antenna delivers widest impedance bandwidth (−10 dB) throughout the operating band of 3.1–20 GHz (of 146% impedance bandwidth) which covers UWB as well as Ku‐band. The antenna also produces ‐18 dB isolation for most of the operating band and ‐16 dB up to 6 GHz. The optimized antenna is fabricated and tested showing |S11| characteristics below −10 dB from 3.1 to 20 GHz band. The dimension of the proposed antenna is 18 × 26 × 1.6 mm3. Results show that the simulated characteristics are in good agreement with the measured counterpart. The designed MIMO antenna is an appropriate candidate for UWB and other wireless applications.

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The progressions in the field of wireless technology can be highly attributed to the development of antennas, which can access high data rates, provide significant gain and uniform radiation characteristics. One such antenna called the Vivaldi antenna has attracted the utmost attention of the researchers owing to its high gain, wide bandwidth, low cross-polarization, and stable radiation characteristics. Over the years, different procedures have been proposed by several researchers to improve the performance of the Vivaldi antennas. Some of these different approaches are feeding mechanisms, integration of slots, dielectric substrate selection, and radiator shape. Correspondingly, the performance of a Vivaldi antenna can be increased by including dielectric lens, parasitic patch in between two radiators, corrugations, as well as metamaterials. This paper gives a systematic identification, location, and analysis of a large number of performance enhancement methods of Vivaldi antenna design depicting their concepts, advantages, drawbacks, and applications. The principal emphasis of this article is to offer an outline of the developments in the design of Vivaldi antennas over the last few years, where the most important offerings, mostly from IEEE publications, have been emphasized. This review work aims to reveal a promising path to antenna researchers for its advancement using Vivaldi antennas.