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In this paper, a novel compact broadband antenna at UHF frequencies is presented with canonical shapes. Hemispherical, conical and cylindrical shapes have all been considered for antenna configuration. The designed antenna provides an instantaneous frequency range from 370 to 5,000 MHz with omnidirectional characteristics. The antenna was simulated in CST Microwave Studio, fabricated and evaluated; the results are presented. The simulated and measurement results are in good agreement. The antenna has voltage standing wave ratio (VSWR) ≤ 1.9:1 in 400–570 MHz, 2,530–3,740 MHz and 4,180–4,620 MHz; it has VSWR ≤ 3:1 over the operating frequency range 370–5,000 MHz and the measured gain varies from -0.6 to 4.5 dBi over the frequency band. The concept of canonical-shaped antenna elements and the incorporation of triple sleeves resulted in a reduction of the length of the antenna by 62% compared to the length of a half-wave dipole antenna designed at the lowest frequency. The antenna can be used for trans-receiving applications in wireless communication.

A novel miniaturized dipole antenna design incorporating triple sleeves and shorting load leading to enhanced bandwidth is proposed in the present work. The Triple Sleeve Dipole Antenna with Shorti...

Ultra-wideband (UWB) phased array antennas are essential for radar, communication, and Electronic Warfare (EW) applications. Systems can operate over wide-band coverage. The high gain systems require wide-band, wide-angle scanning, good radiation pattern, and return loss over a multi-octave bandwidth. This review discusses the problems present in the UWB phased array system, which include mutual coupling, grating lobe rejection, active return loss, gain fluctuation with scanning, and multiple beam generation. In this, the aperture size of the array is limited by the overall gain requirement of the system. On the other hand, low gain systems require a wide-band with a good radiation pattern and axial ratio. Here the matching over wide-band is simpler as it depends on broadband balun configuration. This system has limited bandwidth over scan angles. These antennas are more preferred as wearable antennas in communication applications. This paper mainly discusses the existing UWB phased array antennas such as Vivaldi Arrays, All-metal Arrays, Spiral Arrays, Sinuous Arrays, and Coupled Arrays. This review paper presents a correct direction for selecting the type of antenna in terms of impedance bandwidth, gain, and materials influencing antenna performance, suited for different applications.