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We present a new fractal slot edge antipodal Vivaldi antenna (AVA). When compared to a conventional AVA, it simultaneously extends the low‐end bandwidth limitation, mitigates the side lobe level, and increases the main lobe gain. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:337–346, 2017

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Abstract-We present a new Ultra Wide Band (UWB) TimedArray Transmitter System with Beamforming capability for high-resolution remote acquisition of vital signals. The system consists of four identical channels, where each is formed of a serial topology with three modules: programmable delay circuit (PDC or τ), a novel UWB 5 th Gaussian Derivative order pulse generator circuit (PG), and a planar Vivaldi antenna. The circuit was designed using 0.18µm CMOS standard process and the planar antenna array was designed with filmconductor on Rogers RO3206 substrate. Spice simulations results showed the pulse generation with 104 mVpp amplitude and 500 ps width. The power consumption is 543 µW, and energy consumption 0.27 pJ per pulse using a 2V power supply at a pulse repetition rate (PRR) of 100 MHz. Electromagnetic simulations results, using CST Microwave (MW) Studio 2011, showed the main lobe radiation with a gain maximum of 13.2 dB, 35.5º x 36.7º angular width, and a beam steering between 17º and -11º for azimuthal (θ) angles and 17º and -18º for elevation (φ) angles at the center frequency of 6 GHz.

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The Vivaldi antenna is an ultra‐wideband device that has high gain and directional radiation pattern. This paper performs a comparison of conventional, regular and exponential edges of a Palm Tree Vivaldi antenna that could operate in L and S band frequencies. The conventional coplanar Vivaldi antenna (C‐CVA), regular coplanar Vivaldi antenna (R‐CVA), exponential slot edge coplanar Vivaldi antenna (ESE‐CVA), regular antipodal Vivaldi antenna (R‐AVA) and exponential slot edge antipodal Vivaldi antenna (ESE‐AVA), all with the same dimensions, are compared in terms of reflection coefficient and radiation pattern performance. Gain improvement is achieved as 6.22, 7.64, 7.90, 7.92, and 10.74 dB at 3 GHz respectively for R‐AVA, ESE‐AVA, Convetional ‐ Coplanar Vivaldi Antenna, R‐CVA, and ESE‐CVA. The number, height, and opening rate of slot edges predispose current distribution and radiation pattern of CVA. Our results show that the exponential slot edge coplanar Vivaldi antenna provides the best gain and derives the best side lobe level, which confirmed the possibility of applying the Palm Tree technique to coplanar Vivaldi antennas, in addition to the antipodal ones, as originally proposed.

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