A novel Vivaldi antenna structure is proposed to broaden the bandwidth of the conventional ones. The theory of the equivalent circuit is adopted, and it is deduced that the bandwidth of the antenna can be enhanced by the high chip resistor and short pin in the new structure. An antenna of 62 mm (length) times 70 mm (width)times 0.5 mm (thickness) is designed and fabricated. The measure results show that the bandwidth is 1~ 20 GHz ( VSWR les2), while the gain varies between 0.9 and 7.8 dB. It is indicated that the antenna can be reduced to about a half of the conventional ones.

Design of Resistive Loading Vivaldi Antenna

Microwave imaging for ultra-wideband antenna based cancer detection

Radar operation from the CReSIS Meridian UAV requires a broadband antenna array composed of lightweight, thin, end-fire antenna elements. Toward this goal four Vivaldi antenna designs were simulated, fabricated, and characterized. The final design, dubbed the CReSIS Aerial Vivaldi – Revision A (CAV-A) provides operation over a band extending from 162 MHz to 1.121 GHz. The CAV-A measures 40 cm long, 51 cm wide, and 0.125 inch thick with a weight of 3.22 lbs., thus satisfying the requirements for UAV operation. Due to size, weight, and bandwidth requirements, a simple frequency scaling of a previously published design was unachievable. Most published single-element Vivaldi antenna designs were constrained by traditional thought that says the antenna length should be multiple free-space wavelengths and the antenna width should be a half free-space wavelength, both at the lowest frequency of interest. Contrary to convention, the CAV-A is an electrically small antenna, with an antenna width and length on the order of a quarter free-space wavelength at the lowest frequency of operation.

Development of an Electrically Small Vivaldi Antenna: The CReSIS Aerial Vivaldi (CAV-A)

Abstract Fifth-generation technology is not fully deployed in the world wireless communication till date. Millimeter-wave (mm-wave) band needs to be used due to plenty of available bandwidth and for achieving the goals of 5G such as greater data rate, ultra-high-speed video broadcasting, low latency services, and many more. Wideband antenna is required for 5G applications to access the high speed, low latency Internet services, and ultra-high-definition video streaming. Various bandwidth enhancement techniques have been reported by the researchers for microstrip antennas operating at microwave bands. High link losses, small wavelength, limited coverage, and environmental losses are the major challenges of mm-wave band. To mitigate these issues and satisfy 5G standard, an antenna with wide bandwidth, high gain, narrow steerable beam, high isolation, low side lobe levels, and multiband characteristics is required. Modifications in conventional antenna design techniques are required to achieve broader bandwidth along with stable radiation characteristics, improved gain, and low side lobe levels at mm-wave frequencies. This paper presents the survey of various bandwidth enhancement techniques which has been used in the 5G antennas designed by researchers. Reviews of some wideband 5G antennas with their performance comparisons are also discussed.

Survey of various bandwidth enhancement techniques used for 5G antennas

The development of dielectric notch radiator (DNR) antennas is described with integrated filters for 5G and IoT systems. The DNR is a type of tapered slot antenna (TSA) and is similar to the familiar Vivaldi antenna except that the length of the DNR is much shorter than a Vivaldi. The five step design process for the DNR is given and expands upon prior exponential taper design methods. The optimization and analysis of the microstrip to slot line section uses the finite element method (FEM). The DNR is used for a X-band antenna and line array. The single element simulated and measured return loss and antenna gain pattern are shown. The gain pattern for a four element line array is shown. The DNR is then used for an antenna system operating in the mobile phone and Wi-Fi bands. The antenna is integrated with filters to form a solution with application to 5G and internet of things (IoT) over Zigbee or Wi-Fi systems. The results demonstrate how the DNR antenna can be applied to solve wide band antenna design requirements where antenna length is an important design constraint.

Dielectric notch radiator antennas with integrated filtering for 5G and IoT access

To take maximum advantage of integrated circuit techniques, completely planar geometry should be chosen for tapered slot antennas. This is the reason that the transition used in the present study is microstrip-to-slotline instead of finline to slotline or some other nonplanar transition. The authors investigate the microstrip-to-slotline transition and report on experimental results for Vivaldi antennas of various lengths and output widths. The Vivaldi antennas were designed to operate at 10 GHz and fabricated on Duroid 5870. The directivity in the E- and H-plane for the optimized antenna is shown. The values for the directivity compared favorably to the curves produced by F.J. Zucker (1961) which are the standards for determining whether tapered slot antennas behave as well as optimized traveling-wave antennas. >

J.T. Aberle

Papers

Characterization of Vivaldi antennas utilizing a microstrip-to-slotline transition